HexEdit/HexEditSearchReplaceWidget.py

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

# Copyright (c) 2016 Detlev Offenbach <detlev@die-offenbachs.de>
#

"""
Module implementing a search and replace widget for the hex editor.
"""

from PyQt5.QtCore import pyqtSlot, Qt, QByteArray
from PyQt5.QtWidgets import QWidget

from E5Gui.E5Action import E5Action
from E5Gui import E5MessageBox

import UI.PixmapCache


class HexEditSearchReplaceWidget(QWidget):
    """
    Class implementing a search and replace widget for the hex editor.
    """
    def __init__(self, editor, replace=False, parent=None):
        """
        Constructor
        
        @param editor reference to the hex editor widget
        @type HexEditWidget
        @param replace flag indicating a replace widget
        @type bool
        @param parent reference to the parent widget
        @type QWidget
        """
        super(HexEditSearchReplaceWidget, self).__init__(parent)
        
        self.__replace = replace
        self.__editor = editor
        
        self.__findHistory = []
        if replace:
            from .Ui_HexEditReplaceWidget import Ui_HexEditReplaceWidget
            self.__replaceHistory = []
            self.__ui = Ui_HexEditReplaceWidget()
        else:
            from .Ui_HexEditSearchWidget import Ui_HexEditSearchWidget
            self.__ui = Ui_HexEditSearchWidget()
        self.__ui.setupUi(self)
        
        self.__ui.closeButton.setIcon(UI.PixmapCache.getIcon("close.png"))
        self.__ui.findPrevButton.setIcon(
            UI.PixmapCache.getIcon("1leftarrow.png"))
        self.__ui.findNextButton.setIcon(
            UI.PixmapCache.getIcon("1rightarrow.png"))
        
        if replace:
            self.__ui.replaceButton.setIcon(
                UI.PixmapCache.getIcon("editReplace.png"))
            self.__ui.replaceSearchButton.setIcon(
                UI.PixmapCache.getIcon("editReplaceSearch.png"))
            self.__ui.replaceAllButton.setIcon(
                UI.PixmapCache.getIcon("editReplaceAll.png"))
        
        self.__ui.findtextCombo.setCompleter(None)
        self.__ui.findtextCombo.lineEdit().returnPressed.connect(
            self.__findByReturnPressed)
        if replace:
            self.__ui.replacetextCombo.setCompleter(None)
            self.__ui.replacetextCombo.lineEdit().returnPressed.connect(
                self.on_replaceButton_clicked)
        
        self.findNextAct = E5Action(
            self.tr('Find Next'),
            self.tr('Find Next'),
            0, 0, self, 'hexEditor_search_widget_find_next')
        self.findNextAct.triggered.connect(self.on_findNextButton_clicked)
        self.findNextAct.setEnabled(False)
        self.__ui.findtextCombo.addAction(self.findNextAct)
        
        self.findPrevAct = E5Action(
            self.tr('Find Prev'),
            self.tr('Find Prev'),
            0, 0, self, 'hexEditor_search_widget_find_prev')
        self.findPrevAct.triggered.connect(self.on_findPrevButton_clicked)
        self.findPrevAct.setEnabled(False)
        self.__ui.findtextCombo.addAction(self.findPrevAct)
        
        self.__havefound = False
    
    def on_findtextCombo_editTextChanged(self, txt):
        """
        Private slot to enable/disable the find buttons.
        
        @param txt text of the find text combo (string)
        """
        if not txt:
            self.__ui.findNextButton.setEnabled(False)
            self.findNextAct.setEnabled(False)
            self.__ui.findPrevButton.setEnabled(False)
            self.findPrevAct.setEnabled(False)
            if self.__replace:
                self.__ui.replaceButton.setEnabled(False)
                self.__ui.replaceSearchButton.setEnabled(False)
                self.__ui.replaceAllButton.setEnabled(False)
        else:
            self.__ui.findNextButton.setEnabled(True)
            self.findNextAct.setEnabled(True)
            self.__ui.findPrevButton.setEnabled(True)
            self.findPrevAct.setEnabled(True)
            if self.__replace:
                self.__ui.replaceButton.setEnabled(False)
                self.__ui.replaceSearchButton.setEnabled(False)
                self.__ui.replaceAllButton.setEnabled(True)
    
    def __getContent(self, replace=False):
        """
        Private method to get the contents of the find/replace combo as
        a bytearray.
        
        @param replace flag indicating to retrieve the replace contents
        @type bool
        @return search or replace term as text and binary data
        @rtype tuple of bytearray and str
        """
        if replace:
            textCombo = self.__ui.replacetextCombo
            formatCombo = self.__ui.replaceFormatCombo
            history = self.__replaceHistory
        else:
            textCombo = self.__ui.findtextCombo
            formatCombo = self.__ui.findFormatCombo
            history = self.__findHistory
        
        txt = textCombo.currentText()
        idx = formatCombo.currentIndex()
        if idx == 0:        # hex format
            ba = bytearray(QByteArray.fromHex(
                bytes(txt, encoding="ascii")))
        else:
            ba = bytearray(txt, encoding="utf-8")
        
        # This moves any previous occurrence of this statement to the head
        # of the list and updates the combobox
        if txt in history:
            history.remove(txt)
        history.insert(0, txt)
        textCombo.clear()
        textCombo.addItems(history)
        
        return ba, txt
    
    @pyqtSlot()
    def on_findNextButton_clicked(self):
        """
        Private slot to find the next occurrence.
        """
        self.findPrevNext(False)
    
    @pyqtSlot()
    def on_findPrevButton_clicked(self):
        """
        Private slot to find the previous occurrence.
        """
        self.findPrevNext(True)
    
    def findPrevNext(self, prev=False):
        """
        Public slot to find the next occurrence of the search term.
        
        @param prev flag indicating a backwards search
        @type bool
        @return flag indicating a successful search
        @rtype bool
        """
        if not self.__havefound or not self.__ui.findtextCombo.currentText():
            self.show()
            return
        
        self.__findBackwards = prev
        ba, txt = self.__getContent()
        
        idx = -1
        if len(ba) > 0:
            startIndex = self.__editor.cursorPosition() // 2
            if prev:
                if self.__editor.hasSelection() and \
                        startIndex == self.__editor.getSelectionEnd():
                    # skip to the selection start
                    startIndex = self.__editor.getSelectionBegin()
                idx = self.__editor.lastIndexOf(ba, startIndex)
            else:
                if self.__editor.hasSelection() and \
                        startIndex == self.__editor.getSelectionBegin() - 1:
                    # skip to the selection end
                    startIndex = self.__editor.getSelectionEnd()
                idx = self.__editor.indexOf(ba, startIndex)
        
        if idx >= 0:
            if self.__replace:
                self.__ui.replaceButton.setEnabled(True)
                self.__ui.replaceSearchButton.setEnabled(True)
        else:
            E5MessageBox.information(
                self, self.windowTitle(),
                self.tr("'{0}' was not found.").format(txt))
        
        return idx >= 0
    
    def __findByReturnPressed(self):
        """
        Private slot to handle a return pressed in the find combo.
        """
        if self.__findBackwards:
            self.findPrevNext(True)
        else:
            self.findPrevNext(False)

    @pyqtSlot()
    def on_replaceButton_clicked(self):
        """
        Private slot to replace one occurrence of data.
        """
        self.__doReplace(False)
    
    @pyqtSlot()
    def on_replaceSearchButton_clicked(self):
        """
        Private slot to replace one occurrence of data and search for the next
        one.
        """
        self.__doReplace(True)
    
    def __doReplace(self, searchNext):
        """
        Private method to replace one occurrence of data.
        
        @param searchNext flag indicating to search for the next occurrence
        (boolean).
        """
        # Check enabled status due to dual purpose usage of this method
        if not self.__ui.replaceButton.isEnabled() and \
           not self.__ui.replaceSearchButton.isEnabled():
            return
        
        rba, rtxt = self.__getContent(True)
        
        ok = False
        if self.__editor.hasSelection():
            # we did a successful search before
            startIdx = self.__editor.getSelectionBegin()
            self.__editor.replaceByteArray(startIdx, len(rba), rba)
            
            if searchNext:
                ok = self.findPrevNext(self.__findBackwards)
        
        if not ok:
            self.__ui.replaceButton.setEnabled(False)
            self.__ui.replaceSearchButton.setEnabled(False)
    
    @pyqtSlot()
    def on_replaceAllButton_clicked(self):
        """
        Private slot to replace all occurrences of data.
        """
        replacements = 0
        
        cursorPosition = self.__editor.cursorPosition()
        
        fba, ftxt = self.__getContent(False)
        rba, rtxt = self.__getContent(True)
        
        idx = 0
        while idx >= 0:
            idx = self.__editor.indexOf(fba, idx)
            if idx >= 0:
                self.__editor.replaceByteArray(idx, len(rba), rba)
                idx += len(rba)
                replacements += 1
        
        if replacements:
            E5MessageBox.information(
                self, self.windowTitle(),
                self.tr("Replaced {0} occurrences.")
                .format(replacements))
        else:
            E5MessageBox.information(
                self, self.windowTitle(),
                self.tr("Nothing replaced because '{0}' was not found.")
                .format(ftxt))
        
        self.__editor.setCursorPosition(cursorPosition)
        self.__editor.ensureVisible()
    
    def __showFind(self, text=''):
        """
        Private method to display this widget in find mode.
        
        @param text text to be shown in the findtext edit (string)
        """
        self.__replace = False
        
        self.__ui.findtextCombo.clear()
        self.__ui.findtextCombo.addItems(self.__findHistory)
        self.__ui.findtextCombo.setEditText(text)
        self.__ui.findtextCombo.lineEdit().selectAll()
        self.__ui.findtextCombo.setFocus()
        self.on_findtextCombo_editTextChanged(text)
        
        self.__havefound = True
        self.__findBackwards = False
    
    def __showReplace(self, text=''):
        """
        Private slot to display this widget in replace mode.
        
        @param text text to be shown in the findtext edit
        """
        self.__replace = True
        
        self.__ui.findtextCombo.clear()
        self.__ui.findtextCombo.addItems(self.__findHistory)
        self.__ui.findtextCombo.setEditText(text)
        self.__ui.findtextCombo.lineEdit().selectAll()
        self.__ui.findtextCombo.setFocus()
        self.on_findtextCombo_editTextChanged(text)
        
        self.__ui.replacetextCombo.clear()
        self.__ui.replacetextCombo.addItems(self.__replaceHistory)
        self.__ui.replacetextCombo.setEditText('')
        
        self.__havefound = True
        self.__findBackwards = False
    
    def show(self, text=''):
        """
        Public slot to show the widget.
        
        @param text text to be shown in the findtext edit (string)
        """
        if self.__replace:
            self.__showReplace(text)
        else:
            self.__showFind(text)
        super(HexEditSearchReplaceWidget, self).show()
        self.activateWindow()
    
    @pyqtSlot()
    def on_closeButton_clicked(self):
        """
        Private slot to close the widget.
        """
        self.__editor.setFocus(Qt.OtherFocusReason)
        self.close()

    def keyPressEvent(self, event):
        """
        Protected slot to handle key press events.
        
        @param event reference to the key press event (QKeyEvent)
        """
        if event.key() == Qt.Key_Escape:
            self.close()