IconEditor/IconEditorWindow.py

# -*- coding: utf-8 -*-

# Copyright (c) 2002 - 2010 Detlev Offenbach <detlev@die-offenbachs.de>
#

"""
Module implementing the icon editor main window.
"""

from PyQt4.QtCore import *
from PyQt4.QtGui import *

from E5Gui.E5Action import E5Action, createActionGroup
from E5Gui import E5FileDialog, E5MessageBox

from .IconEditorGrid import IconEditorGrid
from .IconZoomDialog import IconZoomDialog
from .IconEditorPalette import IconEditorPalette

import UI.PixmapCache
import UI.Config

import Preferences

class IconEditorWindow(QMainWindow):
    """
    Class implementing the web browser main window.
    
    @signal editorClosed() emitted after the window was requested to close down
    """
    editorClosed = pyqtSignal()
    
    windows = []
    
    def __init__(self, fileName = "", parent = None, fromEric = False, 
                 initShortcutsOnly = False):
        """
        Constructor
        
        @param fileName name of a file to load on startup (string)
        @param parent parent widget of this window (QWidget)
        @keyparam fromEric flag indicating whether it was called from within 
            eric5 (boolean)
        @keyparam initShortcutsOnly flag indicating to just initialize the keyboard
            shortcuts (boolean)
        """
        QMainWindow.__init__(self, parent)
        self.setObjectName("eric5_icon_editor")
        self.setAttribute(Qt.WA_DeleteOnClose)
        
        self.fromEric = fromEric
        self.initShortcutsOnly = initShortcutsOnly
        self.setWindowIcon(UI.PixmapCache.getIcon("iconEditor.png"))
        
        if self.initShortcutsOnly:
            self.__initActions()
        else:
            self.__editor = IconEditorGrid()
            self.__scrollArea = QScrollArea()
            self.__scrollArea.setWidget(self.__editor)
            self.__scrollArea.viewport().setBackgroundRole(QPalette.Dark)
            self.__scrollArea.viewport().setAutoFillBackground(True)
            self.setCentralWidget(self.__scrollArea)
            
            g = Preferences.getGeometry("IconEditorGeometry")
            if g.isEmpty():
                s = QSize(600, 500)
                self.resize(s)
            else:
                self.restoreGeometry(g)
            
            self.__initActions()
            self.__initMenus()
            self.__initToolbars()
            self.__createStatusBar()
            self.__initFileFilters()
            self.__createPaletteDock()
            
            self.__palette.previewChanged(self.__editor.previewPixmap())
            self.__palette.colorChanged(self.__editor.penColor())
            
            self.__class__.windows.append(self)
            
            state = Preferences.getIconEditor("IconEditorState")
            self.restoreState(state)
            
            self.__editor.imageChanged.connect(self.__modificationChanged)
            self.__editor.positionChanged.connect(self.__updatePosition)
            self.__editor.sizeChanged.connect(self.__updateSize)
            self.__editor.previewChanged.connect(self.__palette.previewChanged)
            self.__editor.colorChanged.connect(self.__palette.colorChanged)
            self.__palette.colorSelected.connect(self.__editor.setPenColor)
            
            self.__setCurrentFile("")
            if fileName:
                self.__loadIconFile(fileName)
            
            self.__checkActions()
    
    def __initFileFilters(self):
        """
        Private method to define the supported image file filters.
        """
        filters = {
            'bmp' : self.trUtf8("Windows Bitmap File (*.bmp)"), 
            'gif' : self.trUtf8("Graphic Interchange Format File (*.gif)"), 
            'ico' : self.trUtf8("Windows Icon File (*.ico)"), 
            'jpg' : self.trUtf8("JPEG File (*.jpg)"), 
            'mng' : self.trUtf8("Multiple-Image Network Graphics File (*.mng)"), 
            'pbm' : self.trUtf8("Portable Bitmap File (*.pbm)"), 
            'pcx' : self.trUtf8("Paintbrush Bitmap File (*.pcx)"), 
            'pgm' : self.trUtf8("Portable Graymap File (*.pgm)"), 
            'png' : self.trUtf8("Portable Network Graphics File (*.png)"), 
            'ppm' : self.trUtf8("Portable Pixmap File (*.ppm)"), 
            'sgi' : self.trUtf8("Silicon Graphics Image File (*.sgi)"), 
            'svg' : self.trUtf8("Scalable Vector Graphics File (*.svg)"), 
            'tga' : self.trUtf8("Targa Graphic File (*.tga)"), 
            'tif' : self.trUtf8("TIFF File (*.tif)"), 
            'xbm' : self.trUtf8("X11 Bitmap File (*.xbm)"), 
            'xpm' : self.trUtf8("X11 Pixmap File (*.xpm)"), 
        }
        
        inputFormats = []
        readFormats = QImageReader.supportedImageFormats()
        for readFormat in readFormats:
            try:
                inputFormats.append(filters[bytes(readFormat).decode()])
            except KeyError:
                pass
        inputFormats.sort()
        inputFormats.append(self.trUtf8("All Files (*)"))
        self.__inputFilter = ';;'.join(inputFormats)
        
        outputFormats = []
        writeFormats = QImageWriter.supportedImageFormats()
        for writeFormat in writeFormats:
            try:
                outputFormats.append(filters[bytes(writeFormat).decode()])
            except KeyError:
                pass
        outputFormats.sort()
        self.__outputFilter = ';;'.join(outputFormats)
        
        self.__defaultFilter = filters['png']
    
    def __initActions(self):
        """
        Private method to define the user interface actions.
        """
        # list of all actions
        self.__actions = []
        
        self.__initFileActions()
        self.__initEditActions()
        self.__initViewActions()
        self.__initToolsActions()
        self.__initHelpActions()
        
    def __initFileActions(self):
        """
        Private method to define the file related user interface actions.
        """
        self.newAct = E5Action(self.trUtf8('New'), 
            UI.PixmapCache.getIcon("new.png"),
            self.trUtf8('&New'), 
            QKeySequence(self.trUtf8("Ctrl+N","File|New")), 
            0, self, 'iconEditor_file_new')
        self.newAct.setStatusTip(self.trUtf8('Create a new icon'))
        self.newAct.setWhatsThis(self.trUtf8(
                """<b>New</b>"""
                """<p>This creates a new icon.</p>"""
        ))
        self.newAct.triggered[()].connect(self.__newIcon)
        self.__actions.append(self.newAct)
        
        self.newWindowAct = E5Action(self.trUtf8('New Window'), 
            UI.PixmapCache.getIcon("newWindow.png"),
            self.trUtf8('New &Window'), 
            0, 0, self, 'iconEditor_file_new_window')
        self.newWindowAct.setStatusTip(self.trUtf8('Open a new icon editor window'))
        self.newWindowAct.setWhatsThis(self.trUtf8(
                """<b>New Window</b>"""
                """<p>This opens a new icon editor window.</p>"""
        ))
        self.newWindowAct.triggered[()].connect(self.__newWindow)
        self.__actions.append(self.newWindowAct)
        
        self.openAct = E5Action(self.trUtf8('Open'), 
            UI.PixmapCache.getIcon("open.png"),
            self.trUtf8('&Open...'), 
            QKeySequence(self.trUtf8("Ctrl+O","File|Open")), 
            0, self, 'iconEditor_file_open')
        self.openAct.setStatusTip(self.trUtf8('Open an icon file for editing'))
        self.openAct.setWhatsThis(self.trUtf8(
                """<b>Open File</b>"""
                """<p>This opens a new icon file for editing."""
                """ It pops up a file selection dialog.</p>"""
        ))
        self.openAct.triggered[()].connect(self.__openIcon)
        self.__actions.append(self.openAct)
        
        self.saveAct = E5Action(self.trUtf8('Save'),
                UI.PixmapCache.getIcon("fileSave.png"),
                self.trUtf8('&Save'),
                QKeySequence(self.trUtf8("Ctrl+S", "File|Save")), 
                0, self, 'iconEditor_file_save')
        self.saveAct.setStatusTip(self.trUtf8('Save the current icon'))
        self.saveAct.setWhatsThis(self.trUtf8(
            """<b>Save File</b>"""
            """<p>Save the contents of the icon editor window.</p>"""
        ))
        self.saveAct.triggered[()].connect(self.__saveIcon)
        self.__actions.append(self.saveAct)
        
        self.saveAsAct = E5Action(self.trUtf8('Save As'), 
            UI.PixmapCache.getIcon("fileSaveAs.png"),
            self.trUtf8('Save &As...'), 
            QKeySequence(self.trUtf8("Shift+Ctrl+S","File|Save As")), 
            0, self, 'iconEditor_file_save_as')
        self.saveAsAct.setStatusTip(
            self.trUtf8('Save the current icon to a new file'))
        self.saveAsAct.setWhatsThis(self.trUtf8(
                """<b>Save As...</b>"""
                """<p>Saves the current icon to a new file.</p>"""
        ))
        self.saveAsAct.triggered[()].connect(self.__saveIconAs)
        self.__actions.append(self.saveAsAct)
        
        self.closeAct = E5Action(self.trUtf8('Close'), 
            UI.PixmapCache.getIcon("close.png"),
            self.trUtf8('&Close'), 
            QKeySequence(self.trUtf8("Ctrl+W","File|Close")), 
            0, self, 'iconEditor_file_close')
        self.closeAct.setStatusTip(self.trUtf8('Close the current icon editor window'))
        self.closeAct.setWhatsThis(self.trUtf8(
                """<b>Close</b>"""
                """<p>Closes the current icon editor window.</p>"""
        ))
        self.closeAct.triggered[()].connect(self.close)
        self.__actions.append(self.closeAct)
        
        self.closeAllAct = E5Action(self.trUtf8('Close All'), 
            self.trUtf8('Close &All'), 
            0, 0, self, 'iconEditor_file_close_all')
        self.closeAllAct.setStatusTip(self.trUtf8('Close all icon editor windows'))
        self.closeAllAct.setWhatsThis(self.trUtf8(
                """<b>Close All</b>"""
                """<p>Closes all icon editor windows except the first one.</p>"""
        ))
        self.closeAllAct.triggered[()].connect(self.__closeAll)
        self.__actions.append(self.closeAllAct)
        
        self.exitAct = E5Action(self.trUtf8('Quit'), 
            UI.PixmapCache.getIcon("exit.png"),
            self.trUtf8('&Quit'), 
            QKeySequence(self.trUtf8("Ctrl+Q","File|Quit")), 
            0, self, 'iconEditor_file_quit')
        self.exitAct.setStatusTip(self.trUtf8('Quit the icon editor'))
        self.exitAct.setWhatsThis(self.trUtf8(
                """<b>Quit</b>"""
                """<p>Quit the icon editor.</p>"""
        ))
        if self.fromEric:
            self.exitAct.triggered[()].connect(self.close)
        else:
            self.exitAct.triggered[()].connect(qApp.closeAllWindows)
        self.__actions.append(self.exitAct)
    
    def __initEditActions(self):
        """
        Private method to create the Edit actions.
        """
        self.undoAct = E5Action(self.trUtf8('Undo'),
                UI.PixmapCache.getIcon("editUndo.png"),
                self.trUtf8('&Undo'),
                QKeySequence(self.trUtf8("Ctrl+Z", "Edit|Undo")), 
                QKeySequence(self.trUtf8("Alt+Backspace", "Edit|Undo")), 
                self, 'iconEditor_edit_undo')
        self.undoAct.setStatusTip(self.trUtf8('Undo the last change'))
        self.undoAct.setWhatsThis(self.trUtf8(
            """<b>Undo</b>"""
            """<p>Undo the last change done.</p>"""
        ))
        self.undoAct.triggered[()].connect(self.__editor.editUndo)
        self.__actions.append(self.undoAct)
        
        self.redoAct = E5Action(self.trUtf8('Redo'),
                UI.PixmapCache.getIcon("editRedo.png"),
                self.trUtf8('&Redo'),
                QKeySequence(self.trUtf8("Ctrl+Shift+Z", "Edit|Redo")), 
                0, self, 'iconEditor_edit_redo')
        self.redoAct.setStatusTip(self.trUtf8('Redo the last change'))
        self.redoAct.setWhatsThis(self.trUtf8(
            """<b>Redo</b>"""
            """<p>Redo the last change done.</p>"""
        ))
        self.redoAct.triggered[()].connect(self.__editor.editRedo)
        self.__actions.append(self.redoAct)
        
        self.cutAct = E5Action(self.trUtf8('Cut'),
                UI.PixmapCache.getIcon("editCut.png"),
                self.trUtf8('Cu&t'),
                QKeySequence(self.trUtf8("Ctrl+X", "Edit|Cut")),
                QKeySequence(self.trUtf8("Shift+Del", "Edit|Cut")),
                self, 'iconEditor_edit_cut')
        self.cutAct.setStatusTip(self.trUtf8('Cut the selection'))
        self.cutAct.setWhatsThis(self.trUtf8(
            """<b>Cut</b>"""
            """<p>Cut the selected image area to the clipboard.</p>"""
        ))
        self.cutAct.triggered[()].connect(self.__editor.editCut)
        self.__actions.append(self.cutAct)
        
        self.copyAct = E5Action(self.trUtf8('Copy'),
                UI.PixmapCache.getIcon("editCopy.png"),
                self.trUtf8('&Copy'),
                QKeySequence(self.trUtf8("Ctrl+C", "Edit|Copy")), 
                QKeySequence(self.trUtf8("Ctrl+Ins", "Edit|Copy")), 
                self, 'iconEditor_edit_copy')
        self.copyAct.setStatusTip(self.trUtf8('Copy the selection'))
        self.copyAct.setWhatsThis(self.trUtf8(
            """<b>Copy</b>"""
            """<p>Copy the selected image area to the clipboard.</p>"""
        ))
        self.copyAct.triggered[()].connect(self.__editor.editCopy)
        self.__actions.append(self.copyAct)
        
        self.pasteAct = E5Action(self.trUtf8('Paste'),
                UI.PixmapCache.getIcon("editPaste.png"),
                self.trUtf8('&Paste'),
                QKeySequence(self.trUtf8("Ctrl+V", "Edit|Paste")), 
                QKeySequence(self.trUtf8("Shift+Ins", "Edit|Paste")), 
                self, 'iconEditor_edit_paste')
        self.pasteAct.setStatusTip(self.trUtf8('Paste the clipboard image'))
        self.pasteAct.setWhatsThis(self.trUtf8(
            """<b>Paste</b>"""
            """<p>Paste the clipboard image.</p>"""
        ))
        self.pasteAct.triggered[()].connect(self.__editor.editPaste)
        self.__actions.append(self.pasteAct)
        
        self.pasteNewAct = E5Action(self.trUtf8('Paste as New'),
                self.trUtf8('Paste as &New'),
                0, 0, self, 'iconEditor_edit_paste_as_new')
        self.pasteNewAct.setStatusTip(self.trUtf8(
            'Paste the clipboard image replacing the current one'))
        self.pasteNewAct.setWhatsThis(self.trUtf8(
            """<b>Paste as New</b>"""
            """<p>Paste the clipboard image replacing the current one.</p>"""
        ))
        self.pasteNewAct.triggered[()].connect(self.__editor.editPasteAsNew)
        self.__actions.append(self.pasteNewAct)
        
        self.deleteAct = E5Action(self.trUtf8('Clear'),
                UI.PixmapCache.getIcon("editDelete.png"),
                self.trUtf8('Cl&ear'),
                QKeySequence(self.trUtf8("Alt+Shift+C", "Edit|Clear")), 
                0,
                self, 'iconEditor_edit_clear')
        self.deleteAct.setStatusTip(self.trUtf8('Clear the icon image'))
        self.deleteAct.setWhatsThis(self.trUtf8(
            """<b>Clear</b>"""
            """<p>Clear the icon image and set it to be completely transparent.</p>"""
        ))
        self.deleteAct.triggered[()].connect(self.__editor.editClear)
        self.__actions.append(self.deleteAct)
        
        self.selectAllAct = E5Action(self.trUtf8('Select All'),
                self.trUtf8('&Select All'),
                QKeySequence(self.trUtf8("Ctrl+A", "Edit|Select All")), 
                0,
                self, 'iconEditor_edit_select_all')
        self.selectAllAct.setStatusTip(self.trUtf8('Select the complete icon image'))
        self.selectAllAct.setWhatsThis(self.trUtf8(
            """<b>Select All</b>"""
            """<p>Selects the complete icon image.</p>"""
        ))
        self.selectAllAct.triggered[()].connect(self.__editor.editSelectAll)
        self.__actions.append(self.selectAllAct)
        
        self.resizeAct = E5Action(self.trUtf8('Change Size'),
                UI.PixmapCache.getIcon("transformResize.png"),
                self.trUtf8('Change Si&ze...'),
                0, 0,
                self, 'iconEditor_edit_change_size')
        self.resizeAct.setStatusTip(self.trUtf8('Change the icon size'))
        self.resizeAct.setWhatsThis(self.trUtf8(
            """<b>Change Size...</b>"""
            """<p>Changes the icon size.</p>"""
        ))
        self.resizeAct.triggered[()].connect(self.__editor.editResize)
        self.__actions.append(self.resizeAct)
        
        self.grayscaleAct = E5Action(self.trUtf8('Grayscale'),
                UI.PixmapCache.getIcon("grayscale.png"),
                self.trUtf8('&Grayscale'),
                0, 0,
                self, 'iconEditor_edit_grayscale')
        self.grayscaleAct.setStatusTip(self.trUtf8('Change the icon to grayscale'))
        self.grayscaleAct.setWhatsThis(self.trUtf8(
            """<b>Grayscale</b>"""
            """<p>Changes the icon to grayscale.</p>"""
        ))
        self.grayscaleAct.triggered[()].connect(self.__editor.grayScale)
        self.__actions.append(self.grayscaleAct)
        
        self.redoAct.setEnabled(False)
        self.__editor.canRedoChanged.connect(self.redoAct.setEnabled)
        
        self.undoAct.setEnabled(False)
        self.__editor.canUndoChanged.connect(self.undoAct.setEnabled)
        
        self.cutAct.setEnabled(False)
        self.copyAct.setEnabled(False)
        self.__editor.selectionAvailable.connect(self.cutAct.setEnabled)
        self.__editor.selectionAvailable.connect(self.copyAct.setEnabled)
        
        self.pasteAct.setEnabled(self.__editor.canPaste())
        self.pasteNewAct.setEnabled(self.__editor.canPaste())
        self.__editor.clipboardImageAvailable.connect(
            self.pasteAct.setEnabled)
        self.__editor.clipboardImageAvailable.connect(
            self.pasteNewAct.setEnabled)
    
    def __initViewActions(self):
        """
        Private method to create the View actions.
        """
        self.zoomInAct = E5Action(self.trUtf8('Zoom in'), 
            UI.PixmapCache.getIcon("zoomIn.png"),
            self.trUtf8('Zoom &in'), 
            QKeySequence(self.trUtf8("Ctrl++", "View|Zoom in")), 
            0, self, 'iconEditor_view_zoom_in')
        self.zoomInAct.setStatusTip(self.trUtf8('Zoom in on the icon'))
        self.zoomInAct.setWhatsThis(self.trUtf8(
                """<b>Zoom in</b>"""
                """<p>Zoom in on the icon. This makes the grid bigger.</p>"""
        ))
        self.zoomInAct.triggered[()].connect(self.__zoomIn)
        self.__actions.append(self.zoomInAct)
        
        self.zoomOutAct = E5Action(self.trUtf8('Zoom out'), 
            UI.PixmapCache.getIcon("zoomOut.png"),
            self.trUtf8('Zoom &out'), 
            QKeySequence(self.trUtf8("Ctrl+-", "View|Zoom out")), 
            0, self, 'iconEditor_view_zoom_out')
        self.zoomOutAct.setStatusTip(self.trUtf8('Zoom out on the icon'))
        self.zoomOutAct.setWhatsThis(self.trUtf8(
                """<b>Zoom out</b>"""
                """<p>Zoom out on the icon. This makes the grid smaller.</p>"""
        ))
        self.zoomOutAct.triggered[()].connect(self.__zoomOut)
        self.__actions.append(self.zoomOutAct)
        
        self.zoomResetAct = E5Action(self.trUtf8('Zoom reset'), 
            UI.PixmapCache.getIcon("zoomReset.png"),
            self.trUtf8('Zoom &reset'), 
            QKeySequence(self.trUtf8("Ctrl+0", "View|Zoom reset")), 
            0, self, 'iconEditor_view_zoom_reset')
        self.zoomResetAct.setStatusTip(self.trUtf8('Reset the zoom of the icon'))
        self.zoomResetAct.setWhatsThis(self.trUtf8(
                """<b>Zoom reset</b>"""
                """<p>Reset the zoom of the icon. """
                """This sets the zoom factor to 100%.</p>"""
        ))
        self.zoomResetAct.triggered[()].connect(self.__zoomReset)
        self.__actions.append(self.zoomResetAct)
        
        self.zoomToAct = E5Action(self.trUtf8('Zoom'),
            UI.PixmapCache.getIcon("zoomTo.png"),
            self.trUtf8('&Zoom...'),
            QKeySequence(self.trUtf8("Ctrl+#", "View|Zoom")), 
            0,
            self, 'iconEditor_view_zoom')
        self.zoomToAct.setStatusTip(self.trUtf8('Zoom the icon'))
        self.zoomToAct.setWhatsThis(self.trUtf8(
                """<b>Zoom</b>"""
                """<p>Zoom the icon. This opens a dialog where the"""
                """ desired zoom factor can be entered.</p>"""
                ))
        self.zoomToAct.triggered[()].connect(self.__zoom)
        self.__actions.append(self.zoomToAct)
        
        self.showGridAct = E5Action(self.trUtf8('Show Grid'),
            UI.PixmapCache.getIcon("grid.png"),
            self.trUtf8('Show &Grid'),
            0, 0,
            self, 'iconEditor_view_show_grid')
        self.showGridAct.setStatusTip(self.trUtf8('Toggle the display of the grid'))
        self.showGridAct.setWhatsThis(self.trUtf8(
                """<b>Show Grid</b>"""
                """<p>Toggle the display of the grid.</p>"""
                ))
        self.showGridAct.triggered[bool].connect(self.__editor.setGridEnabled)
        self.__actions.append(self.showGridAct)
        self.showGridAct.setCheckable(True)
        self.showGridAct.setChecked(self.__editor.isGridEnabled())
    
    def __initToolsActions(self):
        """
        Private method to create the View actions.
        """
        self.esm = QSignalMapper(self)
        self.esm.mapped[int].connect(self.__editor.setTool)
        
        self.drawingActGrp = createActionGroup(self)
        self.drawingActGrp.setExclusive(True)
        
        self.drawPencilAct = E5Action(self.trUtf8('Freehand'), 
            UI.PixmapCache.getIcon("drawBrush.png"),
            self.trUtf8('&Freehand'), 
            0, 0, 
            self.drawingActGrp, 'iconEditor_tools_pencil')
        self.drawPencilAct.setWhatsThis(self.trUtf8(
                """<b>Free hand</b>"""
                """<p>Draws non linear lines.</p>"""
        ))
        self.drawPencilAct.setCheckable(True)
        self.esm.setMapping(self.drawPencilAct, IconEditorGrid.Pencil)
        self.drawPencilAct.triggered[()].connect(self.esm.map)
        self.__actions.append(self.drawPencilAct)
        
        self.drawColorPickerAct = E5Action(self.trUtf8('Color Picker'), 
            UI.PixmapCache.getIcon("colorPicker.png"),
            self.trUtf8('&Color Picker'), 
            0, 0, 
            self.drawingActGrp, 'iconEditor_tools_color_picker')
        self.drawColorPickerAct.setWhatsThis(self.trUtf8(
                """<b>Color Picker</b>"""
                """<p>The color of the pixel clicked on will become """
                """the current draw color.</p>"""
        ))
        self.drawColorPickerAct.setCheckable(True)
        self.esm.setMapping(self.drawColorPickerAct, IconEditorGrid.ColorPicker)
        self.drawColorPickerAct.triggered[()].connect(self.esm.map)
        self.__actions.append(self.drawColorPickerAct)
        
        self.drawRectangleAct = E5Action(self.trUtf8('Rectangle'), 
            UI.PixmapCache.getIcon("drawRectangle.png"),
            self.trUtf8('&Rectangle'), 
            0, 0, 
            self.drawingActGrp, 'iconEditor_tools_rectangle')
        self.drawRectangleAct.setWhatsThis(self.trUtf8(
                """<b>Rectangle</b>"""
                """<p>Draw a rectangle.</p>"""
        ))
        self.drawRectangleAct.setCheckable(True)
        self.esm.setMapping(self.drawRectangleAct, IconEditorGrid.Rectangle)
        self.drawRectangleAct.triggered[()].connect(self.esm.map)
        self.__actions.append(self.drawRectangleAct)
        
        self.drawFilledRectangleAct = E5Action(self.trUtf8('Filled Rectangle'), 
            UI.PixmapCache.getIcon("drawRectangleFilled.png"),
            self.trUtf8('F&illed Rectangle'), 
            0, 0, 
            self.drawingActGrp, 'iconEditor_tools_filled_rectangle')
        self.drawFilledRectangleAct.setWhatsThis(self.trUtf8(
                """<b>Filled Rectangle</b>"""
                """<p>Draw a filled rectangle.</p>"""
        ))
        self.drawFilledRectangleAct.setCheckable(True)
        self.esm.setMapping(self.drawFilledRectangleAct, IconEditorGrid.FilledRectangle)
        self.drawFilledRectangleAct.triggered[()].connect(self.esm.map)
        self.__actions.append(self.drawFilledRectangleAct)
        
        self.drawCircleAct = E5Action(self.trUtf8('Circle'), 
            UI.PixmapCache.getIcon("drawCircle.png"),
            self.trUtf8('Circle'), 
            0, 0, 
            self.drawingActGrp, 'iconEditor_tools_circle')
        self.drawCircleAct.setWhatsThis(self.trUtf8(
                """<b>Circle</b>"""
                """<p>Draw a circle.</p>"""
        ))
        self.drawCircleAct.setCheckable(True)
        self.esm.setMapping(self.drawCircleAct, IconEditorGrid.Circle)
        self.drawCircleAct.triggered[()].connect(self.esm.map)
        self.__actions.append(self.drawCircleAct)
        
        self.drawFilledCircleAct = E5Action(self.trUtf8('Filled Circle'), 
            UI.PixmapCache.getIcon("drawCircleFilled.png"),
            self.trUtf8('Fille&d Circle'), 
            0, 0, 
            self.drawingActGrp, 'iconEditor_tools_filled_circle')
        self.drawFilledCircleAct.setWhatsThis(self.trUtf8(
                """<b>Filled Circle</b>"""
                """<p>Draw a filled circle.</p>"""
        ))
        self.drawFilledCircleAct.setCheckable(True)
        self.esm.setMapping(self.drawFilledCircleAct, IconEditorGrid.FilledCircle)
        self.drawFilledCircleAct.triggered[()].connect(self.esm.map)
        self.__actions.append(self.drawFilledCircleAct)
        
        self.drawEllipseAct = E5Action(self.trUtf8('Ellipse'), 
            UI.PixmapCache.getIcon("drawEllipse.png"),
            self.trUtf8('&Ellipse'), 
            0, 0, 
            self.drawingActGrp, 'iconEditor_tools_ellipse')
        self.drawEllipseAct.setWhatsThis(self.trUtf8(
                """<b>Ellipse</b>"""
                """<p>Draw an ellipse.</p>"""
        ))
        self.drawEllipseAct.setCheckable(True)
        self.esm.setMapping(self.drawEllipseAct, IconEditorGrid.Ellipse)
        self.drawEllipseAct.triggered[()].connect(self.esm.map)
        self.__actions.append(self.drawEllipseAct)
        
        self.drawFilledEllipseAct = E5Action(self.trUtf8('Filled Ellipse'), 
            UI.PixmapCache.getIcon("drawEllipseFilled.png"),
            self.trUtf8('Fille&d Elli&pse'), 
            0, 0, 
            self.drawingActGrp, 'iconEditor_tools_filled_ellipse')
        self.drawFilledEllipseAct.setWhatsThis(self.trUtf8(
                """<b>Filled Ellipse</b>"""
                """<p>Draw a filled ellipse.</p>"""
        ))
        self.drawFilledEllipseAct.setCheckable(True)
        self.esm.setMapping(self.drawFilledEllipseAct, IconEditorGrid.FilledEllipse)
        self.drawFilledEllipseAct.triggered[()].connect(self.esm.map)
        self.__actions.append(self.drawFilledEllipseAct)
        
        self.drawFloodFillAct = E5Action(self.trUtf8('Flood Fill'), 
            UI.PixmapCache.getIcon("drawFill.png"),
            self.trUtf8('Fl&ood Fill'), 
            0, 0, 
            self.drawingActGrp, 'iconEditor_tools_flood_fill')
        self.drawFloodFillAct.setWhatsThis(self.trUtf8(
                """<b>Flood Fill</b>"""
                """<p>Fill adjoining pixels with the same color with """
                """the current color.</p>"""
        ))
        self.drawFloodFillAct.setCheckable(True)
        self.esm.setMapping(self.drawFloodFillAct, IconEditorGrid.Fill)
        self.drawFloodFillAct.triggered[()].connect(self.esm.map)
        self.__actions.append(self.drawFloodFillAct)
        
        self.drawLineAct = E5Action(self.trUtf8('Line'), 
            UI.PixmapCache.getIcon("drawLine.png"),
            self.trUtf8('&Line'), 
            0, 0, 
            self.drawingActGrp, 'iconEditor_tools_line')
        self.drawLineAct.setWhatsThis(self.trUtf8(
                """<b>Line</b>"""
                """<p>Draw a line.</p>"""
        ))
        self.drawLineAct.setCheckable(True)
        self.esm.setMapping(self.drawLineAct, IconEditorGrid.Line)
        self.drawLineAct.triggered[()].connect(self.esm.map)
        self.__actions.append(self.drawLineAct)
        
        self.drawEraserAct = E5Action(self.trUtf8('Eraser (Transparent)'), 
            UI.PixmapCache.getIcon("drawEraser.png"),
            self.trUtf8('Eraser (&Transparent)'), 
            0, 0, 
            self.drawingActGrp, 'iconEditor_tools_eraser')
        self.drawEraserAct.setWhatsThis(self.trUtf8(
                """<b>Eraser (Transparent)</b>"""
                """<p>Erase pixels by setting them to transparent.</p>"""
        ))
        self.drawEraserAct.setCheckable(True)
        self.esm.setMapping(self.drawEraserAct, IconEditorGrid.Rubber)
        self.drawEraserAct.triggered[()].connect(self.esm.map)
        self.__actions.append(self.drawEraserAct)
        
        self.drawRectangleSelectionAct = E5Action(self.trUtf8('Rectangular Selection'), 
            UI.PixmapCache.getIcon("selectRectangle.png"),
            self.trUtf8('Rect&angular Selection'), 
            0, 0, 
            self.drawingActGrp, 'iconEditor_tools_selection_rectangle')
        self.drawRectangleSelectionAct.setWhatsThis(self.trUtf8(
                """<b>Rectangular Selection</b>"""
                """<p>Select a rectangular section of the icon using the mouse.</p>"""
        ))
        self.drawRectangleSelectionAct.setCheckable(True)
        self.esm.setMapping(self.drawRectangleSelectionAct, 
                            IconEditorGrid.RectangleSelection)
        self.drawRectangleSelectionAct.triggered[()].connect(self.esm.map)
        self.__actions.append(self.drawRectangleSelectionAct)
        
        self.drawCircleSelectionAct = E5Action(self.trUtf8('Circular Selection'), 
            UI.PixmapCache.getIcon("selectCircle.png"),
            self.trUtf8('Rect&angular Selection'), 
            0, 0, 
            self.drawingActGrp, 'iconEditor_tools_selection_circle')
        self.drawCircleSelectionAct.setWhatsThis(self.trUtf8(
                """<b>Circular Selection</b>"""
                """<p>Select a circular section of the icon using the mouse.</p>"""
        ))
        self.drawCircleSelectionAct.setCheckable(True)
        self.esm.setMapping(self.drawCircleSelectionAct, 
                            IconEditorGrid.CircleSelection)
        self.drawCircleSelectionAct.triggered[()].connect(self.esm.map)
        self.__actions.append(self.drawCircleSelectionAct)
        
        self.drawPencilAct.setChecked(True)
    
    def __initHelpActions(self):
        """
        Private method to create the Help actions.
        """
        self.aboutAct = E5Action(self.trUtf8('About'),
                self.trUtf8('&About'),
                0, 0, self, 'iconEditor_help_about')
        self.aboutAct.setStatusTip(self.trUtf8('Display information about this software'))
        self.aboutAct.setWhatsThis(self.trUtf8(
            """<b>About</b>"""
            """<p>Display some information about this software.</p>"""))
        self.aboutAct.triggered[()].connect(self.__about)
        self.__actions.append(self.aboutAct)
        
        self.aboutQtAct = E5Action(self.trUtf8('About Qt'),
                self.trUtf8('About &Qt'), 
                0, 0, self, 'iconEditor_help_about_qt')
        self.aboutQtAct.setStatusTip(
            self.trUtf8('Display information about the Qt toolkit'))
        self.aboutQtAct.setWhatsThis(self.trUtf8(
            """<b>About Qt</b>"""
            """<p>Display some information about the Qt toolkit.</p>"""
        ))
        self.aboutQtAct.triggered[()].connect(self.__aboutQt)
        self.__actions.append(self.aboutQtAct)
        
        self.whatsThisAct = E5Action(self.trUtf8('What\'s This?'), 
            UI.PixmapCache.getIcon("whatsThis.png"),
            self.trUtf8('&What\'s This?'), 
            QKeySequence(self.trUtf8("Shift+F1","Help|What's This?'")), 
            0, self, 'iconEditor_help_whats_this')
        self.whatsThisAct.setStatusTip(self.trUtf8('Context sensitive help'))
        self.whatsThisAct.setWhatsThis(self.trUtf8(
                """<b>Display context sensitive help</b>"""
                """<p>In What's This? mode, the mouse cursor shows an arrow with a"""
                """ question mark, and you can click on the interface elements to get"""
                """ a short description of what they do and how to use them. In"""
                """ dialogs, this feature can be accessed using the context help button"""
                """ in the titlebar.</p>"""
        ))
        self.whatsThisAct.triggered[()].connect(self.__whatsThis)
        self.__actions.append(self.whatsThisAct)
    
    def __initMenus(self):
        """
        Private method to create the menus.
        """
        mb = self.menuBar()
        
        menu = mb.addMenu(self.trUtf8('&File'))
        menu.setTearOffEnabled(True)
        menu.addAction(self.newAct)
        menu.addAction(self.newWindowAct)
        menu.addAction(self.openAct)
        menu.addSeparator()
        menu.addAction(self.saveAct)
        menu.addAction(self.saveAsAct)
        menu.addSeparator()
        menu.addAction(self.closeAct)
        menu.addAction(self.closeAllAct)
        menu.addSeparator()
        menu.addAction(self.exitAct)
        
        menu = mb.addMenu(self.trUtf8("&Edit"))
        menu.setTearOffEnabled(True)
        menu.addAction(self.undoAct)
        menu.addAction(self.redoAct)
        menu.addSeparator()
        menu.addAction(self.cutAct)
        menu.addAction(self.copyAct)
        menu.addAction(self.pasteAct)
        menu.addAction(self.pasteNewAct)
        menu.addAction(self.deleteAct)
        menu.addSeparator()
        menu.addAction(self.selectAllAct)
        menu.addSeparator()
        menu.addAction(self.resizeAct)
        menu.addAction(self.grayscaleAct)
        
        menu = mb.addMenu(self.trUtf8('&View'))
        menu.setTearOffEnabled(True)
        menu.addAction(self.zoomInAct)
        menu.addAction(self.zoomResetAct)
        menu.addAction(self.zoomOutAct)
        menu.addAction(self.zoomToAct)
        menu.addSeparator()
        menu.addAction(self.showGridAct)
        
        menu = mb.addMenu(self.trUtf8('&Tools'))
        menu.setTearOffEnabled(True)
        menu.addAction(self.drawPencilAct)
        menu.addAction(self.drawColorPickerAct)
        menu.addAction(self.drawRectangleAct)
        menu.addAction(self.drawFilledRectangleAct)
        menu.addAction(self.drawCircleAct)
        menu.addAction(self.drawFilledCircleAct)
        menu.addAction(self.drawEllipseAct)
        menu.addAction(self.drawFilledEllipseAct)
        menu.addAction(self.drawFloodFillAct)
        menu.addAction(self.drawLineAct)
        menu.addAction(self.drawEraserAct)
        menu.addSeparator()
        menu.addAction(self.drawRectangleSelectionAct)
        menu.addAction(self.drawCircleSelectionAct)
        
        mb.addSeparator()
        
        menu = mb.addMenu(self.trUtf8("&Help"))
        menu.addAction(self.aboutAct)
        menu.addAction(self.aboutQtAct)
        menu.addSeparator()
        menu.addAction(self.whatsThisAct)
    
    def __initToolbars(self):
        """
        Private method to create the toolbars.
        """
        filetb = self.addToolBar(self.trUtf8("File"))
        filetb.setObjectName("FileToolBar")
        filetb.setIconSize(UI.Config.ToolBarIconSize)
        filetb.addAction(self.newAct)
        filetb.addAction(self.newWindowAct)
        filetb.addAction(self.openAct)
        filetb.addSeparator()
        filetb.addAction(self.saveAct)
        filetb.addAction(self.saveAsAct)
        filetb.addSeparator()
        filetb.addAction(self.closeAct)
        filetb.addAction(self.exitAct)
        
        edittb = self.addToolBar(self.trUtf8("Edit"))
        edittb.setObjectName("EditToolBar")
        edittb.setIconSize(UI.Config.ToolBarIconSize)
        edittb.addAction(self.undoAct)
        edittb.addAction(self.redoAct)
        edittb.addSeparator()
        edittb.addAction(self.cutAct)
        edittb.addAction(self.copyAct)
        edittb.addAction(self.pasteAct)
        edittb.addSeparator()
        edittb.addAction(self.resizeAct)
        edittb.addAction(self.grayscaleAct)
        
        viewtb = self.addToolBar(self.trUtf8("View"))
        viewtb.setObjectName("ViewToolBar")
        viewtb.setIconSize(UI.Config.ToolBarIconSize)
        viewtb.addAction(self.zoomInAct)
        viewtb.addAction(self.zoomResetAct)
        viewtb.addAction(self.zoomOutAct)
        viewtb.addAction(self.zoomToAct)
        viewtb.addSeparator()
        viewtb.addAction(self.showGridAct)
        
        toolstb = self.addToolBar(self.trUtf8("Tools"))
        toolstb.setObjectName("ToolsToolBar")
        toolstb.setIconSize(UI.Config.ToolBarIconSize)
        toolstb.addAction(self.drawPencilAct)
        toolstb.addAction(self.drawColorPickerAct)
        toolstb.addAction(self.drawRectangleAct)
        toolstb.addAction(self.drawFilledRectangleAct)
        toolstb.addAction(self.drawCircleAct)
        toolstb.addAction(self.drawFilledCircleAct)
        toolstb.addAction(self.drawEllipseAct)
        toolstb.addAction(self.drawFilledEllipseAct)
        toolstb.addAction(self.drawFloodFillAct)
        toolstb.addAction(self.drawLineAct)
        toolstb.addAction(self.drawEraserAct)
        toolstb.addSeparator()
        toolstb.addAction(self.drawRectangleSelectionAct)
        toolstb.addAction(self.drawCircleSelectionAct)
        
        helptb = self.addToolBar(self.trUtf8("Help"))
        helptb.setObjectName("HelpToolBar")
        helptb.setIconSize(UI.Config.ToolBarIconSize)
        helptb.addAction(self.whatsThisAct)
    
    def __createStatusBar(self):
        """
        Private method to initialize the status bar.
        """
        self.__statusBar = self.statusBar()
        self.__statusBar.setSizeGripEnabled(True)

        self.__sbZoom = QLabel(self.__statusBar)
        self.__statusBar.addPermanentWidget(self.__sbZoom)
        self.__sbZoom.setWhatsThis(self.trUtf8(
            """<p>This part of the status bar displays the current zoom factor.</p>"""
        ))
        self.__updateZoom()

        self.__sbSize = QLabel(self.__statusBar)
        self.__statusBar.addPermanentWidget(self.__sbSize)
        self.__sbSize.setWhatsThis(self.trUtf8(
            """<p>This part of the status bar displays the icon size.</p>"""
        ))
        self.__updateSize(*self.__editor.iconSize())

        self.__sbPos = QLabel(self.__statusBar)
        self.__statusBar.addPermanentWidget(self.__sbPos)
        self.__sbPos.setWhatsThis(self.trUtf8(
            """<p>This part of the status bar displays the cursor position.</p>"""
        ))
        self.__updatePosition(0, 0)
    
    def __createPaletteDock(self):
        """
        Private method to initialize the palette dock widget.
        """
        self.__paletteDock = QDockWidget(self)
        self.__paletteDock.setObjectName("paletteDock")
        self.__paletteDock.setFeatures(
            QDockWidget.DockWidgetFeatures(QDockWidget.AllDockWidgetFeatures))
        self.__paletteDock.setWindowTitle("Palette")
        self.__palette = IconEditorPalette()
        self.__paletteDock.setWidget(self.__palette)
        self.addDockWidget(Qt.RightDockWidgetArea, self.__paletteDock)
    
    def closeEvent(self, evt):
        """
        Private event handler for the close event.
        
        @param evt the close event (QCloseEvent)
                <br />This event is simply accepted after the history has been
                saved and all window references have been deleted.
        """
        if self.__maybeSave():
            self.__editor.shutdown()
            
            state = self.saveState()
            Preferences.setIconEditor("IconEditorState", state)

            Preferences.setGeometry("IconEditorGeometry", self.saveGeometry())
            
            try:
                del self.__class__.windows[self.__class__.windows.index(self)]
            except ValueError:
                pass
            
            if not self.fromEric:
                Preferences.syncPreferences()
            
            evt.accept()
            self.editorClosed.emit()
        else:
            evt.ignore()
    
    def __newIcon(self):
        """
        Private slot to create a new icon.
        """
        if self.__maybeSave():
            self.__editor.editNew()
            self.__setCurrentFile("")
        
        self.__checkActions()
    
    def __newWindow(self):
        """
        Public slot called to open a new icon editor window.
        """
        ie = IconEditorWindow(parent = self.parent(), fromEric = self.fromEric)
        ie.show()
    
    def __openIcon(self):
        """
        Private slot to open an icon file.
        """
        if self.__maybeSave():
            fileName = E5FileDialog.getOpenFileNameAndFilter(
                self,
                self.trUtf8("Open icon file"),
                "",
                self.__inputFilter,
                self.__defaultFilter)[0]
            if fileName:
                self.__loadIconFile(fileName)
        self.__checkActions()
    
    def __saveIcon(self):
        """
        Private slot to save the icon.
        """
        if not self.__fileName:
            return self.__saveIconAs()
        else:
            return self.__saveIconFile(self.__fileName)
    
    def __saveIconAs(self):
        """
        Private slot to save the icon with a new name.
        """
        fileName, selectedFilter = E5FileDialog.getSaveFileNameAndFilter(
            self,
            self.trUtf8("Save icon file"),
            "",
            self.__outputFilter,
            self.__defaultFilter,
            QFileDialog.Options(QFileDialog.DontConfirmOverwrite))
        if not fileName:
            return False
        
        ext = QFileInfo(fileName).suffix()
        if not ext:
            ex = selectedFilter.split("(*")[1].split(")")[0]
            if ex:
                fileName += ex
        if QFileInfo(fileName).exists():
            res = E5MessageBox.yesNo(self,
                self.trUtf8("Save icon file"),
                self.trUtf8("<p>The file <b>{0}</b> already exists."
                            " Overwrite it?</p>").format(fileName),
                icon = E5MessageBox.Warning)
            if not res:
                return False
        
        return self.__saveIconFile(fileName)
    
    def __closeAll(self):
        """
        Private slot to close all other windows.
        """
        for win in self.__class__.windows[:]:
            if win != self:
                win.close()
    
    def __loadIconFile(self, fileName):
        """
        Private method to load an icon file.
        
        @param fileName name of the icon file to load (string).
        """
        file= QFile(fileName)
        if not file.exists():
            E5MessageBox.warning(self, self.trUtf8("eric5 Icon Editor"),
                                self.trUtf8("The file '{0}' does not exist.")\
                                    .format(fileName))
            return
        
        if not file.open(QFile.ReadOnly):
            E5MessageBox.warning(self, self.trUtf8("eric5 Icon Editor"),
                                self.trUtf8("Cannot read file '{0}:\n{1}.")\
                                    .format(fileName, file.errorString()))
            return
        file.close()
        
        img = QImage(fileName)
        self.__editor.setIconImage(img, clearUndo = True)
        self.__setCurrentFile(fileName)

    def __saveIconFile(self, fileName):
        """
        Private method to save to the given file.
        
        @param fileName name of the file to save to (string)
        @return flag indicating success (boolean)
        """
        file = QFile(fileName)
        if not file.open(QFile.WriteOnly):
            E5MessageBox.warning(self, self.trUtf8("eric5 Icon Editor"),
                                self.trUtf8("Cannot write file '{0}:\n{1}.")\
                                    .format(fileName, file.errorString()))
        
            self.__checkActions()
            
            return False
        
        img = self.__editor.iconImage()
        res = img.save(file)
        file.close()
        
        if not res:
            E5MessageBox.warning(self, self.trUtf8("eric5 Icon Editor"),
                                self.trUtf8("Cannot write file '{0}:\n{1}.")\
                                    .format(fileName, file.errorString()))
        
            self.__checkActions()
            
            return False
        
        self.__editor.setDirty(False, setCleanState = True)
        
        self.__setCurrentFile(fileName)
        self.__statusBar.showMessage(self.trUtf8("Icon saved"), 2000)
        
        self.__checkActions()
        
        return True

    def __setCurrentFile(self, fileName):
        """
        Private method to register the file name of the current file.
        
        @param fileName name of the file to register (string)
        """
        self.__fileName = fileName
        
        if not self.__fileName:
            shownName = self.trUtf8("Untitled")
        else:
            shownName = self.__strippedName(self.__fileName)
        
        self.setWindowTitle(self.trUtf8("{0}[*] - {1}")\
                            .format(shownName, self.trUtf8("Icon Editor")))
        
        self.setWindowModified(self.__editor.isDirty())
    
    def __strippedName(self, fullFileName):
        """
        Private method to return the filename part of the given path.
        
        @param fullFileName full pathname of the given file (string)
        @return filename part (string)
        """
        return QFileInfo(fullFileName).fileName()
    
    def __maybeSave(self):
        """
        Private method to ask the user to save the file, if it was modified.
        
        @return flag indicating, if it is ok to continue (boolean)
        """
        if self.__editor.isDirty():
            ret = E5MessageBox.okToClearData(self,
                self.trUtf8("eric5 Icon Editor"),
                self.trUtf8("""The icon image has unsaved changes."""), 
                self.__saveIcon)
            if not ret:
                return False
        return True
    
    def __checkActions(self):
        """
        Private slot to check some actions for their enable/disable status.
        """
        self.saveAct.setEnabled(self.__editor.isDirty())

    def __modificationChanged(self, m):
        """
        Private slot to handle the modificationChanged signal. 
        
        @param m modification status
        """
        self.setWindowModified(m)
        self.__checkActions()
    
    def __updatePosition(self, x, y):
        """
        Private slot to show the current cursor position.
        
        @param x x-coordinate (integer)
        @param y y-coordinate (integer)
        """
        self.__sbPos.setText("{0:d}, {1:d}".format(x + 1, y + 1))
    
    def __updateSize(self, w, h):
        """
        Private slot to show the current icon size.
        
        @param w width of the icon (integer)
        @param h height of the icon (integer)
        """
        self.__sbSize.setText("{0:d} x {1:d}".format(w, h))
    
    def __updateZoom(self):
        """
        Private slot to show the current zoom factor.
        """
        zoom = self.__editor.zoomFactor()
        self.__sbZoom.setText("{0:d} %".format(zoom * 100))
        self.zoomOutAct.setEnabled(self.__editor.zoomFactor() > 1)
    
    def __zoomIn(self):
        """
        Private slot called to handle the zoom in action.
        """
        self.__editor.setZoomFactor(self.__editor.zoomFactor() + 1)
        self.__updateZoom()
    
    def __zoomOut(self):
        """
        Private slot called to handle the zoom out action.
        """
        self.__editor.setZoomFactor(self.__editor.zoomFactor() - 1)
        self.__updateZoom()
    
    def __zoomReset(self):
        """
        Private slot called to handle the zoom reset action.
        """
        self.__editor.setZoomFactor(1)
        self.__updateZoom()
    
    def __zoom(self):
        """
        Private method to handle the zoom action.
        """
        dlg = IconZoomDialog(self.__editor.zoomFactor(), self)
        if dlg.exec_() == QDialog.Accepted:
            self.__editor.setZoomFactor(dlg.getZoomFactor())
            self.__updateZoom()
    
    def __about(self):
        """
        Private slot to show a little About message.
        """
        E5MessageBox.about(self, self.trUtf8("About eric5 Icon Editor"),
            self.trUtf8("The eric5 Icon Editor is a simple editor component"
                        " to perform icon drawing tasks."))
    
    def __aboutQt(self):
        """
        Private slot to handle the About Qt dialog.
        """
        E5MessageBox.aboutQt(self, "eric5 Icon Editor")
    
    def __whatsThis(self):
        """
        Private slot called in to enter Whats This mode.
        """
        QWhatsThis.enterWhatsThisMode()