Snapshot/SnapWidget.py

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

# Copyright (c) 2012 Detlev Offenbach <detlev@die-offenbachs.de>
#

"""
Module implementing the snapshot widget.
"""

#
# SnapWidget and it's associated modules are PyQt4 ports of Ksnapshot.
#

import os

from PyQt4.QtCore import pyqtSlot, QFile, QFileInfo, QTimer, QPoint, QMimeData, Qt, \
    QEvent, QRegExp
from PyQt4.QtGui import QWidget, QImageWriter, QApplication, QPixmap, QCursor, QDrag, \
    QShortcut, QKeySequence, QDesktopServices

from E5Gui import E5FileDialog, E5MessageBox

from .Ui_SnapWidget import Ui_SnapWidget

from .SnapshotRegionGrabber import SnapshotRegionGrabber
from .SnapshotFreehandGrabber import SnapshotFreehandGrabber
from .SnapshotTimer import SnapshotTimer

import UI.PixmapCache
import Preferences


class SnapWidget(QWidget, Ui_SnapWidget):
    """
    Class implementing the snapshot widget.
    """
    ModeFullscreen = 0
    ModeScreen = 1
    ModeRectangle = 2
    ModeFreehand = 3
    ModeEllipse = 4
    
    def __init__(self, parent=None):
        """
        Constructor
        
        @param parent reference to the parent widget (QWidget)
        """
        super().__init__(parent)
        self.setupUi(self)
        
        self.saveButton.setIcon(UI.PixmapCache.getIcon("fileSaveAs.png"))
        self.takeButton.setIcon(UI.PixmapCache.getIcon("cameraPhoto.png"))
        self.copyButton.setIcon(UI.PixmapCache.getIcon("editCopy.png"))
        self.setWindowIcon(UI.PixmapCache.getIcon("ericSnap.png"))
        
        self.modeCombo.addItem(self.trUtf8("Fullscreen"),
                               SnapWidget.ModeFullscreen)
        self.modeCombo.addItem(self.trUtf8("Rectangular Selection"),
                               SnapWidget.ModeRectangle)
        self.modeCombo.addItem(self.trUtf8("Ellipical Selection"),
                               SnapWidget.ModeEllipse)
        self.modeCombo.addItem(self.trUtf8("Freehand Selection"),
                               SnapWidget.ModeFreehand)
        if QApplication.desktop().numScreens() > 1:
            self.modeCombo.addItem(self.trUtf8("Current Screen"),
                                   SnapWidget.ModeScreen)
        self.__mode = int(Preferences.Prefs.settings.value("Snapshot/Mode", 0))
        index = self.modeCombo.findData(self.__mode)
        if index == -1:
            index = 0
        self.modeCombo.setCurrentIndex(index)
        
        self.__delay = int(Preferences.Prefs.settings.value( "Snapshot/Delay", 0))
        self.delaySpin.setValue(self.__delay)
        
        self.__filename = Preferences.Prefs.settings.value( "Snapshot/Filename",
            os.path.join(
                QDesktopServices.storageLocation(QDesktopServices.PicturesLocation),
                self.trUtf8("snapshot") + "1.png"))
        
        self.__grabber = None
        self.__snapshot = QPixmap()
        self.__savedPosition = QPoint()
        self.__modified = False
        
        self.__grabberWidget = QWidget(None, Qt.X11BypassWindowManagerHint)
        self.__grabberWidget.move(-10000, -10000)
        self.__grabberWidget.installEventFilter(self);
        
        self.__initFileFilters()
        
        self.__initShortcuts()
        
        self.preview.startDrag.connect(self.__dragSnapshot)
        
        self.__grabTimer = SnapshotTimer()
        self.__grabTimer.timeout.connect(self.__grabTimerTimeout)
        self.__updateTimer = QTimer()
        self.__updateTimer.setSingleShot(True)
        self.__updateTimer.timeout.connect(self.__updatePreview)
        
        self.__updateCaption()
        self.takeButton.setFocus()
    
    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)"),
        }
        
        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 __initShortcuts(self):
        """
        Private method to initialize the keyboard shortcuts.
        """
        self.__quitShortcut = QShortcut(QKeySequence(QKeySequence.Quit), self, self.close)
        
        self.__copyShortcut = QShortcut(QKeySequence(QKeySequence.Copy), self,
            self.copyButton.animateClick)
        
        self.__quickSaveShortcut = QShortcut(QKeySequence(Qt.Key_Q), self,
            self.__quickSave)
        
        self.__save1Shortcut = QShortcut(QKeySequence(QKeySequence.Save), self,
            self.saveButton.animateClick)
        self.__save2Shortcut = QShortcut(QKeySequence(Qt.Key_S), self,
            self.saveButton.animateClick)
        
        self.__grab1Shortcut = QShortcut(QKeySequence(QKeySequence.New), self,
            self.takeButton.animateClick)
        self.__grab2Shortcut = QShortcut(QKeySequence(Qt.Key_N), self,
            self.takeButton.animateClick)
        self.__grab3Shortcut = QShortcut(QKeySequence(Qt.Key_Space), self,
            self.takeButton.animateClick)
    
    def __quickSave(self):
        """
        Private slot to save the snapshot bypassing the file selection dialog.
        """
        if not self.__snapshot.isNull():
            while os.path.exists(self.__filename):
                self.__autoIncFilename()
            
            if self.__saveImage(self.__filename):
                self.__modified = False
                self.__autoIncFilename()
                self.__updateCaption()
    
    @pyqtSlot()
    def on_saveButton_clicked(self):
        """
        Private slot to save the snapshot.
        """
        if not self.__snapshot.isNull():
            while os.path.exists(self.__filename):
                self.__autoIncFilename()
            
            fileName, selectedFilter = E5FileDialog.getSaveFileNameAndFilter(
                self,
                self.trUtf8("Save Snapshot"),
                self.__filename,
                self.__outputFilter,
                self.__defaultFilter,
                E5FileDialog.Options(E5FileDialog.DontConfirmOverwrite))
            if not fileName:
                return
            
            ext = QFileInfo(fileName).suffix()
            if not ext:
                ex = selectedFilter.split("(*")[1].split(")")[0]
                if ex:
                    fileName += ex
            
            if self.__saveImage(fileName):
                self.__modified = False
                self.__filename = fileName
                self.__autoIncFilename()
                self.__updateCaption()
    
    def __saveImage(self, fileName):
        """
        Private method to save the snapshot.
        
        @param fileName name of the file to save to (string)
        @return flag indicating success (boolean)
        """
        if QFileInfo(fileName).exists():
            res = E5MessageBox.yesNo(self,
                self.trUtf8("Save Snapshot"),
                self.trUtf8("<p>The file <b>{0}</b> already exists."
                            " Overwrite it?</p>").format(fileName),
                icon=E5MessageBox.Warning)
            if not res:
                return False
        
        file = QFile(fileName)
        if not file.open(QFile.WriteOnly):
            E5MessageBox.warning(self, self.trUtf8("Save Snapshot"),
                                self.trUtf8("Cannot write file '{0}:\n{1}.")\
                                    .format(fileName, file.errorString()))
            return False
        
        ok = self.__snapshot.save(file)
        file.close()
        
        if not ok:
            E5MessageBox.warning(self, self.trUtf8("Save Snapshot"),
                                self.trUtf8("Cannot write file '{0}:\n{1}.")\
                                    .format(fileName, file.errorString()))
        
        return ok
    
    def __autoIncFilename(self):
        """
        Private method to auto-increment the file name.
        """
        # Extract the file name
        name = os.path.basename(self.__filename)
        
        # If the name contains a number, then increment it.
        numSearch = QRegExp("(^|[^\\d])(\\d+)")     # We want to match as far left as
                                                    # possible, and when the number is
                                                    # at the start of the name.
        
        # Does it have a number?
        start = numSearch.lastIndexIn(name)
        if start != -1:
            # It has a number, increment it.
            start = numSearch.pos(2)    # Only the second group is of interest.
            numAsStr = numSearch.capturedTexts()[2]
            number = "{0:0{width}d}".format(int(numAsStr) + 1, width=len(numAsStr))
            name = name[:start] + number + name[start+len(numAsStr):]
        else:
            # no number
            start = name.rfind('.')
            if start != -1:
                # has a '.' somewhere, e.g. it has an extension
                name = name [:start] + '1' + name[start:]
            else:
                # no extension, just tack it on to the end
                name += '1'
        
        self.__filename = os.path.join(os.path.dirname(self.__filename), name)
        self.__updateCaption()
    
    @pyqtSlot()
    def on_takeButton_clicked(self):
        """
        Private slot to take a snapshot.
        """
        self.__mode = self.modeCombo.itemData(self.modeCombo.currentIndex())
        self.__delay = self.delaySpin.value()
        
        self.__savedPosition = self.pos()
        self.hide()
        
        if self.__delay:
            self.__grabTimer.start(self.__delay)
        else:
            QTimer.singleShot(200, self.__startUndelayedGrab)
    
    def __grabTimerTimeout(self):
        """
        Private slot to perform a delayed grab operation.
        """
        if self.__mode == SnapWidget.ModeRectangle:
            self.__grabRectangle()
        elif self.__mode == SnapWidget.ModeEllipse:
            self.__grabEllipse()
        elif self.__mode == SnapWidget.ModeFreehand:
            self.__grabFreehand()
        else:
            self.__performGrab()
    
    def __startUndelayedGrab(self):
        """
        Private slot to perform an undelayed grab operation.
        """
        if self.__mode == SnapWidget.ModeRectangle:
            self.__grabRectangle()
        elif self.__mode == SnapWidget.ModeEllipse:
            self.__grabEllipse()
        elif self.__mode == SnapWidget.ModeFreehand:
            self.__grabFreehand()
        else:
            self.__grabberWidget.show()
            self.__grabberWidget.grabMouse(Qt.CrossCursor)
    
    def __grabRectangle(self):
        """
        Private method to grab a rectangular screen region.
        """
        self.__grabber = SnapshotRegionGrabber(mode=SnapshotRegionGrabber.Rectangle)
        self.__grabber.grabbed.connect(self.__captured)
    
    def __grabEllipse(self):
        """
        Private method to grab an elliptical screen region.
        """
        self.__grabber = SnapshotRegionGrabber(mode=SnapshotRegionGrabber.Ellipse)
        self.__grabber.grabbed.connect(self.__captured)
    
    def __grabFreehand(self):
        """
        Private method to grab a non-rectangular screen region.
        """
        self.__grabber = SnapshotFreehandGrabber()
        self.__grabber.grabbed.connect(self.__captured)
    
    def __performGrab(self):
        """
        Private method to perform a screen grab other than a selected region.
        """
        self.__grabberWidget.releaseMouse()
        self.__grabberWidget.hide()
        self.__grabTimer.stop()
        
        if self.__mode == SnapWidget.ModeFullscreen:
            desktop = QApplication.desktop()
            self.__snapshot = QPixmap.grabWindow(desktop.winId(),
                desktop.x(), desktop.y(), desktop.width(), desktop.height())
        elif self.__mode == SnapWidget.ModeScreen:
            desktop = QApplication.desktop()
            screenId = desktop.screenNumber(QCursor.pos())
            geom = desktop.screenGeometry(screenId)
            x = geom.x()
            y = geom.y()
            self.__snapshot = QPixmap.grabWindow(
                desktop.winId(), x, y, geom.width(), geom.height())
        else:
            self.__snapshot = QPixmap()
        
        self.__redisplay()
        self.__modified = True
        self.__updateCaption()
    
    def __redisplay(self):
        """
        Private method to redisplay the window.
        """
        self.__updatePreview()
        QApplication.restoreOverrideCursor()
        if not self.__savedPosition.isNull():
            self.move(self.__savedPosition)
        self.show()
        
        self.saveButton.setEnabled(not self.__snapshot.isNull())
        self.copyButton.setEnabled(not self.__snapshot.isNull())
    
    @pyqtSlot()
    def on_copyButton_clicked(self):
        """
        Private slot to copy the snapshot to the clipboard.
        """
        QApplication.clipboard().setPixmap(self.preview.pixmap())
    
    def __captured(self, pixmap):
        """
        Private slot to show a preview of the snapshot.
        
        @param pixmap pixmap of the snapshot (QPixmap)
        """
        self.__grabber.close()
        self.__snapshot = QPixmap(pixmap)
        
        self.__grabber.grabbed.disconnect(self.__captured)
        self.__grabber = None
        
        self.__redisplay()
        self.__modified = True
        self.__updateCaption()
    
    def __updatePreview(self):
        """
        Private slot to update the preview picture.
        """
        self.preview.setToolTip(
            self.trUtf8("Preview of the snapshot image ({0:n} x {1:n})").format(
            self.__snapshot.width(), self.__snapshot.height()))
        self.preview.setPreview(self.__snapshot)
        self.preview.adjustSize()
    
    def resizeEvent(self, evt):
        """
        Protected method handling a resizing of the window.
        
        @param evt resize event (QResizeEvent)
        """
        self.__updateTimer.start(200)
    
    def __dragSnapshot(self):
        """
        Private slot handling the dragging of the preview picture.
        """
        drag = QDrag(self)
        mimeData = QMimeData()
        mimeData.setImageData(self.__snapshot)
        drag.setMimeData(mimeData)
        drag.setPixmap(self.preview.pixmap())
        drag.exec_(Qt.CopyAction)
    
    def eventFilter(self, obj, evt):
        """
        Public method to handle event for other objects.
        
        @param obj reference to the object (QObject)
        @param evt reference to the event (QEvent)
        @return flag indicating that the event should be filtered out (boolean)
        """
        if obj == self.__grabberWidget and evt.type() == QEvent.MouseButtonPress:
            if QWidget.mouseGrabber() != self.__grabberWidget:
                return False
            if evt.button() == Qt.LeftButton:
                self.__performGrab()
        
        return False
    
    def closeEvent(self, evt):
        """
        Protected method handling the close event.
        
        @param evt close event (QCloseEvent)
        """
        if self.__modified:
            res = E5MessageBox.question(self,
                self.trUtf8("eric5 Snapshot"),
                self.trUtf8("""The application contains an unsaved snapshot."""),
                E5MessageBox.StandardButtons(
                    E5MessageBox.Abort | \
                    E5MessageBox.Discard | \
                    E5MessageBox.Save))
            if res == E5MessageBox.Abort:
                evt.ignore()
                return
            elif res == E5MessageBox.Save:
                self.on_saveButton_clicked()
        
        Preferences.Prefs.settings.setValue("Snapshot/Delay", self.delaySpin.value())
        Preferences.Prefs.settings.setValue("Snapshot/Mode",
            self.modeCombo.itemData(self.modeCombo.currentIndex()))
        Preferences.Prefs.settings.setValue("Snapshot/Filename", self.__filename)
        Preferences.Prefs.settings.sync()
    
    def __updateCaption(self):
        """
        Private method to update the window caption.
        """
        self.setWindowTitle("{0}[*] - {1}".format(
            os.path.basename(self.__filename),
            self.trUtf8("eric5 Snapshot")))
        self.setWindowModified(self.__modified)
        self.pathNameEdit.setText(os.path.dirname(self.__filename))