#!/usr/bin/env python


#############################################################################
##
## Copyright (C) 2013 Riverbank Computing Limited.
## Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
## All rights reserved.
##
## This file is part of the examples of PyQt.
##
## $QT_BEGIN_LICENSE:BSD$
## You may use this file under the terms of the BSD license as follows:
##
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## modification, are permitted provided that the following conditions are
## met:
##   * Redistributions of source code must retain the above copyright
##     notice, this list of conditions and the following disclaimer.
##   * Redistributions in binary form must reproduce the above copyright
##     notice, this list of conditions and the following disclaimer in
##     the documentation and/or other materials provided with the
##     distribution.
##   * Neither the name of Nokia Corporation and its Subsidiary(-ies) nor
##     the names of its contributors may be used to endorse or promote
##     products derived from this software without specific prior written
##     permission.
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## THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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## OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
## $QT_END_LICENSE$
##
#############################################################################


import unicodedata

from PyQt5.QtCore import pyqtSignal, QSize, Qt
from PyQt5.QtGui import (QClipboard, QFont, QFontDatabase, QFontMetrics,
        QPainter)
from PyQt5.QtWidgets import (QApplication, QCheckBox, QComboBox, QFontComboBox,
        QHBoxLayout, QLabel, QLineEdit, QMainWindow, QPushButton, QScrollArea,
        QToolTip, QVBoxLayout, QWidget)


class CharacterWidget(QWidget):

    characterSelected = pyqtSignal(str)

    def __init__(self, parent=None):
        super(CharacterWidget, self).__init__(parent)

        self.displayFont = QFont()
        self.squareSize = 24
        self.columns = 16
        self.lastKey = -1
        self.setMouseTracking(True)

    def updateFont(self, fontFamily):
        self.displayFont.setFamily(fontFamily)
        self.squareSize = max(24, QFontMetrics(self.displayFont).xHeight() * 3)
        self.adjustSize()
        self.update()

    def updateSize(self, fontSize):
        fontSize, _ = fontSize.toInt()
        self.displayFont.setPointSize(fontSize)
        self.squareSize = max(24, QFontMetrics(self.displayFont).xHeight() * 3)
        self.adjustSize()
        self.update() 

    def updateStyle(self, fontStyle):
        fontDatabase = QFontDatabase()
        oldStrategy = self.displayFont.styleStrategy()
        self.displayFont = fontDatabase.font(self.displayFont.family(),
                fontStyle, self.displayFont.pointSize())
        self.displayFont.setStyleStrategy(oldStrategy)
        self.squareSize = max(24, QFontMetrics(self.displayFont).xHeight() * 3)
        self.adjustSize()
        self.update()

    def updateFontMerging(self, enable):
        if enable:
            self.displayFont.setStyleStrategy(QFont.PreferDefault)
        else:
            self.displayFont.setStyleStrategy(QFont.NoFontMerging)
        self.adjustSize()
        self.update()

    def sizeHint(self):
        return QSize(self.columns * self.squareSize,
                (65536 / self.columns) * self.squareSize)

    def mouseMoveEvent(self, event):
        widgetPosition = self.mapFromGlobal(event.globalPos())
        key = (widgetPosition.y() // self.squareSize) * self.columns + widgetPosition.x() // self.squareSize

        text = '<p>Character: <span style="font-size: 24pt; font-family: %s">%s</span><p>Value: 0x%x' % (self.displayFont.family(), self._chr(key), key)
        QToolTip.showText(event.globalPos(), text, self)

    def mousePressEvent(self, event):
        if event.button() == Qt.LeftButton:
            self.lastKey = (event.y() // self.squareSize) * self.columns + event.x() // self.squareSize
            key_ch = self._chr(self.lastKey)

            if unicodedata.category(key_ch) != 'Cn':
                self.characterSelected.emit(key_ch)
            self.update()
        else:
            super(CharacterWidget, self).mousePressEvent(event)

    def paintEvent(self, event):
        painter = QPainter(self)
        painter.fillRect(event.rect(), Qt.white)
        painter.setFont(self.displayFont)

        redrawRect = event.rect()
        beginRow = redrawRect.top() // self.squareSize
        endRow = redrawRect.bottom() // self.squareSize
        beginColumn = redrawRect.left() // self.squareSize
        endColumn = redrawRect.right() // self.squareSize

        painter.setPen(Qt.gray)
        for row in range(beginRow, endRow + 1):
            for column in range(beginColumn, endColumn + 1):
                painter.drawRect(column * self.squareSize,
                        row * self.squareSize, self.squareSize,
                        self.squareSize)

        fontMetrics = QFontMetrics(self.displayFont)
        painter.setPen(Qt.black)
        for row in range(beginRow, endRow + 1):
            for column in range(beginColumn, endColumn + 1):
                key = row * self.columns + column
                painter.setClipRect(column * self.squareSize,
                        row * self.squareSize, self.squareSize,
                        self.squareSize)

                if key == self.lastKey:
                    painter.fillRect(column * self.squareSize + 1,
                            row * self.squareSize + 1, self.squareSize,
                            self.squareSize, Qt.red)

                key_ch = self._chr(key)
                painter.drawText(column * self.squareSize + (self.squareSize / 2) - fontMetrics.width(key_ch) / 2,
                        row * self.squareSize + 4 + fontMetrics.ascent(),
                        key_ch)

    @staticmethod
    def _chr(codepoint):
        try:
            # Python v2.
            return unichr(codepoint)
        except NameError:
            # Python v3.
            return chr(codepoint)


class MainWindow(QMainWindow):
    def __init__(self):
        super(MainWindow, self).__init__()

        centralWidget = QWidget()

        fontLabel = QLabel("Font:")
        self.fontCombo = QFontComboBox()
        sizeLabel = QLabel("Size:")
        self.sizeCombo = QComboBox()
        styleLabel = QLabel("Style:")
        self.styleCombo = QComboBox()
        fontMergingLabel = QLabel("Automatic Font Merging:")
        self.fontMerging = QCheckBox()
        self.fontMerging.setChecked(True)

        self.scrollArea = QScrollArea()
        self.characterWidget = CharacterWidget()
        self.scrollArea.setWidget(self.characterWidget)

        self.findStyles(self.fontCombo.currentFont())
        self.findSizes(self.fontCombo.currentFont())

        self.lineEdit = QLineEdit()
        clipboardButton = QPushButton("&To clipboard")

        self.clipboard = QApplication.clipboard()

        self.fontCombo.currentFontChanged.connect(self.findStyles)
        self.fontCombo.activated[str].connect(self.characterWidget.updateFont)
        self.styleCombo.activated[str].connect(self.characterWidget.updateStyle)
        self.sizeCombo.currentIndexChanged[str].connect(self.characterWidget.updateSize)
        self.characterWidget.characterSelected.connect(self.insertCharacter)
        clipboardButton.clicked.connect(self.updateClipboard)

        controlsLayout = QHBoxLayout()
        controlsLayout.addWidget(fontLabel)
        controlsLayout.addWidget(self.fontCombo, 1)
        controlsLayout.addWidget(sizeLabel)
        controlsLayout.addWidget(self.sizeCombo, 1)
        controlsLayout.addWidget(styleLabel)
        controlsLayout.addWidget(self.styleCombo, 1)
        controlsLayout.addWidget(fontMergingLabel)
        controlsLayout.addWidget(self.fontMerging, 1)
        controlsLayout.addStretch(1)

        lineLayout = QHBoxLayout()
        lineLayout.addWidget(self.lineEdit, 1)
        lineLayout.addSpacing(12)
        lineLayout.addWidget(clipboardButton)

        centralLayout = QVBoxLayout()
        centralLayout.addLayout(controlsLayout)
        centralLayout.addWidget(self.scrollArea, 1)
        centralLayout.addSpacing(4)
        centralLayout.addLayout(lineLayout)
        centralWidget.setLayout(centralLayout)

        self.setCentralWidget(centralWidget)
        self.setWindowTitle("Character Map")

    def findStyles(self, font):
        fontDatabase = QFontDatabase()
        currentItem = self.styleCombo.currentText()
        self.styleCombo.clear()

        for style in fontDatabase.styles(font.family()):
            self.styleCombo.addItem(style)

        styleIndex = self.styleCombo.findText(currentItem)
        if styleIndex == -1:
            self.styleCombo.setCurrentIndex(0)
        else:
            self.styleCombo.setCurrentIndex(styleIndex)

    def findSizes(self, font):
        fontDatabase = QFontDatabase()
        currentSize = self.sizeCombo.currentText()
        self.sizeCombo.blockSignals(True)
        self.sizeCombo.clear()

        if fontDatabase.isSmoothlyScalable(font.family(), fontDatabase.styleString(font)):
            for size in QFontDatabase.standardSizes():
                self.sizeCombo.addItem(str(size))
                self.sizeCombo.setEditable(True)
        else:
            for size in fontDatabase.smoothSizes(font.family(), fontDatabase.styleString(font)):
                self.sizeCombo.addItem(str(size))
                self.sizeCombo.setEditable(False)

        self.sizeCombo.blockSignals(False)

        sizeIndex = self.sizeCombo.findText(currentSize)
        if sizeIndex == -1:
            self.sizeCombo.setCurrentIndex(max(0, self.sizeCombo.count() / 3))
        else:
            self.sizeCombo.setCurrentIndex(sizeIndex)

    def insertCharacter(self, character):
        self.lineEdit.insert(character)

    def updateClipboard(self):
        self.clipboard.setText(self.lineEdit.text(), QClipboard.Clipboard)
        self.clipboard.setText(self.lineEdit.text(), QClipboard.Selection)


if __name__ == '__main__':

    import sys

    app = QApplication(sys.argv)
    window = MainWindow()
    window.show()
    sys.exit(app.exec_())