Source code for gsdview.qt4draw

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

### Copyright (C) 2008-2012 Antonio Valentino <a_valentino@users.sf.net>

### This file is part of GSDView.

### GSDView is free software; you can redistribute it and/or modify
### it under the terms of the GNU General Public License as published by
### the Free Software Foundation; either version 2 of the License, or
### (at your option) any later version.

### GSDView is distributed in the hope that it will be useful,
### but WITHOUT ANY WARRANTY; without even the implied warranty of
### MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
### GNU General Public License for more details.

### You should have received a copy of the GNU General Public License
### along with GSDView; if not, write to the Free Software
### Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA.


'''Drawing components for Qt4.'''


from qt import QtCore, QtGui

from .mousemanager import MouseMode  # , RubberBandMode


__author__ = 'Antonio Valentino <a_valentino@users.sf.net>'
__date__ = '$Date$'
__revision__ = '$Revision$'


### Graphics Items ############################################################
def _highlightSelectedGraphicsItem(item, painter, option, boundingrect=None):
    '''Highlights item as selected.

    .. note:: This function is a duplicate of
              qt_graphicsItem_highlightSelected() in
              qgraphicssvgitem.cpp!

    '''

    murect = painter.transform().mapRect(QtCore.QRectF(0, 0, 1, 1))
    if abs(max(murect.width(), murect.height())) <= 0.000000000001:
        return

    if boundingrect is None:
        boundingrect = item.boundingRect()

    mbrect = painter.transform().mapRect(boundingrect)
    if min(mbrect.width(), mbrect.height()) < 1.0:
        return

    try:
        #if item.type() in (QGraphicsEllipseItem.Type,
        #                   QGraphicsPathItem.Type,
        #                   QGraphicsPolygonItem.Type,
        #                   QGraphicsRectItem.Type,
        #                   QGraphicsSimpleTextItem.Type,
        #                   QGraphicsLineItem.Type):
        itemPenWidth = item.pen().widthF()
    except AttributeError:
        itemPenWidth = 1.0

    pad = itemPenWidth / 2
    penWidth = 0            # cosmetic pen

    fgcolor = option.palette.windowText().color()
    # ensure good contrast against fgcolor
    bgcolor = QtGui.QColor(0 if fgcolor.red() > 127 else 255,
                           0 if fgcolor.green() > 127 else 255,
                           0 if fgcolor.blue() > 127 else 255)

    painter.setPen(QtGui.QPen(bgcolor, penWidth, QtCore.Qt.SolidLine))
    painter.setBrush(QtCore.Qt.NoBrush)
    painter.drawRect(boundingrect.adjusted(pad, pad, -pad, -pad))

    painter.setPen(QtGui.QPen(option.palette.windowText(), 0,
                              QtCore.Qt.DashLine))
    painter.setBrush(QtCore.Qt.NoBrush)
    painter.drawRect(boundingrect.adjusted(pad, pad, -pad, -pad))


class GraphicsPointItem(QtGui.QAbstractGraphicsShapeItem):
    '''Qt graphics item for point merkers.

    Draw a symbol that scales its size according to the zoom level in
    order to keep approximatively constant size.
    Original size and maximum scaling factor are configurable.

    .. note:: currently the only symbol supported is a filled circle
              (pen and brush are configurable).

    .. note:: this class don't depends on OGR so it can be moved in a
              module out of the gdalbackend.

    '''

    Type = QtGui.QGraphicsItem.UserType + 100

    def __init__(self, x=None, y=None, radius=None, parent=None, scene=None,
                 **kargs):
        super(GraphicsPointItem, self).__init__(parent, scene, **kargs)

        # @COMPATIBILITY: Qt >= 4.6.0 needs this flag to be set otherwise the
        #                 exact exposedRect is not computed
        # @SEEALSO: ItemUsesExtendedStyleOption item at
        # http://doc.qt.nokia.com/4.6/qgraphicsitem.html#GraphicsItemFlag-enum
        try:
            self.setFlag(QtGui.QGraphicsItem.ItemUsesExtendedStyleOptions)
        except AttributeError:
            ItemUsesExtendedStyleOptions = 0x200
            self.setFlag(ItemUsesExtendedStyleOptions)

        if None not in (x, y):
            self.setPos(x, y)

        self._radius = 1
        if radius is not None:
            self._radius = radius

        self._maxfact = 10

        brush = self.brush()
        brush.setStyle(QtCore.Qt.SolidPattern)
        self.setBrush(brush)

    def radius(self):
        return self._radius

    def setRadius(self, radius):
        if radius < 0:
            raise ValueError('invalid radius: "%s"' % radius)
        self._radius = float(radius)

    def maxFactor(self):
        return self._maxfact

    def setMaxFactor(self, maxfact):
        if maxfact < 0:
            raise ValueError('invalid saling factor: "%s"' % maxfact)
        self._maxfact = float(maxfact)

    def type(self):
        return self.Type

    def boundingRect(self):
        penwidth = self.pen().widthF()
        radius = self._maxfact * self._radius
        diameter = 2. * radius
        return QtCore.QRectF(-radius - penwidth / 2, -radius - penwidth / 2,
                             diameter + penwidth, diameter + penwidth)

    def paint(self, painter, option, widget):
        levelOfDetail = option.levelOfDetailFromTransform(painter.transform())

        painter.setPen(self.pen())
        painter.setBrush(self.brush())

        radius = min(self._radius / levelOfDetail,
                     self._radius * self._maxfact)
        painter.drawEllipse(QtCore.QPointF(0, 0), radius, radius)

        if option.state & QtGui.QStyle.State_Selected:
            penwidth = self.pen().widthF()
            diameter = 2. * radius
            rect = QtCore.QRectF(-radius - penwidth / 2,
                                 -radius - penwidth / 2,
                                 diameter + penwidth, diameter + penwidth)

            _highlightSelectedGraphicsItem(self, painter, option, rect)


class GraphicsItemGroup(QtGui.QGraphicsItemGroup):
    '''Qt graphics item group with common style.'''

    Type = QtGui.QGraphicsItem.UserType + 101

    def __init__(self, parent=None, scene=None, **kargs):
        super(GraphicsItemGroup, self).__init__(parent, scene, **kargs)

        self._pen = QtGui.QPen()
        self._brush = QtGui.QBrush()

    def addToGroup(self, item):
        super(GraphicsItemGroup, self).addToGroup(item)
        try:
            item.setPen(self._pen)
            item.setBrusH(self._brush)
        except AttributeError:
            pass

    # @TODO: check pyqtProperty
    def pen(self):
        return self._pen

    def setPen(self, pen):
        if not isinstance(pen, QtGui.QPen):
            raise TypeError('invalid pen object: %s' % pen)
        self._pen = pen

        for item in self.childItems():
            try:
                item.setPen(pen)
            except AttributeError:
                pass

    def brush(self):
        return self._brush

    def setBrush(self, brush):
        if not isinstance(brush, QtGui.QBrush):
            raise TypeError('invalid brush object: %s' % brush)
        self._brush = brush

        for item in self.childItems():
            try:
                item.setBrush(brush)
            except AttributeError:
                pass


### Drawing tools #############################################################
class DrawPointMode(MouseMode):
    dragmode = QtGui.QGraphicsView.NoDrag
    cursor = QtCore.Qt.CrossCursor
    icon = ':/trolltech/styles/commonstyle/images/standardbutton-yes-128.png'
    label = 'Draw Point'
    name = 'drawPoint'

    def sceneEventFilter(self, obj, event):
        if (event.type() == QtCore.QEvent.GraphicsSceneMousePress and
                                    event.button() == QtCore.Qt.LeftButton):
            return True

        elif (event.type() == QtCore.QEvent.GraphicsSceneMouseRelease and
                                    event.button() == QtCore.Qt.LeftButton):
            pen = QtGui.QPen()
            pen.setColor(QtCore.Qt.red)

            brush = QtGui.QBrush()
            brush.setColor(QtCore.Qt.red)
            brush.setStyle(QtCore.Qt.SolidPattern)

            RADIUS = 3
            point = event.scenePos()
            item = GraphicsPointItem(point.x(), point.y(), RADIUS)
            item.setPen(pen)
            item.setBrush(brush)
            item.setFlag(QtGui.QGraphicsItem.ItemIsSelectable, True)
            item.setFlag(QtGui.QGraphicsItem.ItemIsMovable, True)
            obj.addItem(item)
            return True

        return False


class DrawLineMode(MouseMode):
    dragmode = QtGui.QGraphicsView.NoDrag
    cursor = QtCore.Qt.CrossCursor
    icon = ':/trolltech/dialogs/qprintpreviewdialog/images/fit-width-24.png'
    label = 'Draw Line'
    name = 'drawLine'

    def __init__(self, parent=None):
        super(DrawLineMode, self).__init__(parent)
        self.rubberband = None
        self.pen = QtGui.QPen()
        self.pen.setWidth(1)
        self.pen.setColor(QtCore.Qt.red)

    def sceneEventFilter(self, obj, event):
        if (event.type() == QtCore.QEvent.GraphicsSceneMousePress and
                                    event.button() == QtCore.Qt.LeftButton):
            assert(self.rubberband is None)
            self.rubberband = QtGui.QRubberBand(QtGui.QRubberBand.Line)
            self.rubberband.setGeometry(QtCore.QRect(event.screenPos(),
                                                     QtCore.QSize()))
            self.rubberband.show()
            return True

        if (event.type() == QtCore.QEvent.GraphicsSceneMouseRelease and
                                    event.button() == QtCore.Qt.LeftButton):
            assert(self.rubberband is not None)
            self.rubberband.hide()
            self.rubberband = None
            line = QtCore.QLineF(
                            event.buttonDownScenePos(QtCore.Qt.LeftButton),
                            event.scenePos())
            item = obj.addLine(line, self.pen)
            item.setFlag(QtGui.QGraphicsItem.ItemIsSelectable, True)
            item.setFlag(QtGui.QGraphicsItem.ItemIsMovable, True)
            return True

        elif (event.type() == QtCore.QEvent.GraphicsSceneMouseMove and
                                bool(event.buttons() & QtCore.Qt.LeftButton)):
            assert(self.rubberband is not None)
            rect = QtCore.QRect(
                            event.buttonDownScreenPos(QtCore.Qt.LeftButton),
                            event.screenPos()).normalized()
            self.rubberband.setGeometry(rect)
            return True

        return False


#~ class DrawPolygonMode(MouseMode):
    #~ dragmode = QtGui.QGraphicsView.NoDrag
    #~ cursor = QtCore.Qt.CrossCursor
    #~ icon = ':/trolltech/dialogs/qprintpreviewdialog/images/fit-width-24.png'
    #~ label = 'Draw Line'
    #~ name = 'drawLine'

    #~ def __init__(self, parent=None):
        #~ super(DrawPolygonMode, self).__init__(parent)
        #~ self.rubberband = None
        #~ self.pen = QtGui.QPen()
        #~ self.pen.setWidth(1)
        #~ self.pen.setColor(QtCore.Qt.red)
        #~ self.brush = QtGui.QBrush()
        #~ #self.brush.setStyle(QtCore.Qt.SolidPattern)
        #~ #self.brush.setColor(QtCore.Qt.red)

    #~ def sceneEventFilter(self, obj, event):
        #~ if (event.type() == QtCore.QEvent.GraphicsSceneMousePress and
                                    #~ event.button() == QtCore.Qt.LeftButton):
            #~ assert(self.rubberband is None)
            #~ self.rubberband = QtGui.QRubberBand(QtGui.QRubberBand.Line)
            #~ self.rubberband.setGeometry(QtCore.QRect(event.screenPos(),
                                                     #~ QtCore.QSize()))
            #~ self.rubberband.show()
            #~ return True

        #~ if (event.type() == QtCore.QEvent.GraphicsSceneMouseRelease and
                                    #~ event.button() == QtCore.Qt.LeftButton):
            #~ assert(self.rubberband is not None)
            #~ self.rubberband.hide()
            #~ self.rubberband = None
            #~ line = QtCore.QLineF(
                            #~ event.buttonDownScenePos(QtCore.Qt.LeftButton),
                            #~ event.scenePos())
            #~ item = obj.addLine(line, self.pen)
            #~ item.setFlag(QtGui.QGraphicsItem.ItemIsSelectable, True)
            #~ item.setFlag(QtGui.QGraphicsItem.ItemIsMovable, True)
            #~ return True

        #~ elif (event.type() == QtCore.QEvent.GraphicsSceneMouseMove and
                                #~ bool(event.buttons() & QtCore.Qt.LeftButton)):
            #~ assert(self.rubberband is not None)
            #~ rect = QtCore.QRect(
                            #~ event.buttonDownScreenPos(QtCore.Qt.LeftButton),
                            #~ event.screenPos()).normalized()
            #~ self.rubberband.setGeometry(rect)
            #~ return True

        #~ return False


class DrawRectMode(MouseMode):
    dragmode = QtGui.QGraphicsView.NoDrag
    cursor = QtCore.Qt.CrossCursor
    icon = ':/trolltech/styles/commonstyle/images/media-stop-32.png'
    label = 'Draw Rect'
    name = 'drawRect'

    def __init__(self, parent=None):
        super(DrawRectMode, self).__init__(parent)
        self.rubberband = None
        self.pen = QtGui.QPen()
        self.pen.setWidth(1)
        self.pen.setColor(QtCore.Qt.red)
        self.brush = QtGui.QBrush()
        #self.brush.setStyle(QtCore.Qt.SolidPattern)
        #self.brush.setColor(QtCore.Qt.red)

    def sceneEventFilter(self, obj, event):
        if (event.type() == QtCore.QEvent.GraphicsSceneMousePress and
                                    event.button() == QtCore.Qt.LeftButton):
            assert(self.rubberband is None)
            self.rubberband = QtGui.QRubberBand(QtGui.QRubberBand.Rectangle)
            self.rubberband.setGeometry(QtCore.QRect(event.screenPos(),
                                                     QtCore.QSize()))
            self.rubberband.show()
            return True

        if (event.type() == QtCore.QEvent.GraphicsSceneMouseRelease and
                                    event.button() == QtCore.Qt.LeftButton):
            assert(self.rubberband is not None)
            self.rubberband.hide()
            self.rubberband = None
            rect = QtCore.QRectF(
                            event.buttonDownScenePos(QtCore.Qt.LeftButton),
                            event.scenePos()).normalized()
            item = obj.addRect(rect, self.pen, self.brush)
            item.setFlag(QtGui.QGraphicsItem.ItemIsSelectable, True)
            item.setFlag(QtGui.QGraphicsItem.ItemIsMovable, True)
            return True

        elif (event.type() == QtCore.QEvent.GraphicsSceneMouseMove and
                                bool(event.buttons() & QtCore.Qt.LeftButton)):
            assert(self.rubberband is not None)
            rect = QtCore.QRect(
                            event.buttonDownScreenPos(QtCore.Qt.LeftButton),
                            event.screenPos()).normalized()
            self.rubberband.setGeometry(rect)
            return True

        return False


class DrawEllipseMode(MouseMode):
    dragmode = QtGui.QGraphicsView.NoDrag
    cursor = QtCore.Qt.CrossCursor
    icon = ':/trolltech/styles/commonstyle/images/standardbutton-no-128.png'
    label = 'Draw Ellipse'
    name = 'drawEllipse'

    def __init__(self, parent=None):
        super(DrawEllipseMode, self).__init__(parent)
        self.rubberband = None
        self.pen = QtGui.QPen()
        self.pen.setWidth(1)
        self.pen.setColor(QtCore.Qt.red)
        self.brush = QtGui.QBrush()
        #self.brush.setStyle(QtCore.Qt.SolidPattern)
        #self.brush.setColor(QtCore.Qt.red)

    def sceneEventFilter(self, obj, event):
        if (event.type() == QtCore.QEvent.GraphicsSceneMousePress and
                                    event.button() == QtCore.Qt.LeftButton):
            assert(self.rubberband is None)
            self.rubberband = QtGui.QRubberBand(QtGui.QRubberBand.Rectangle)
            self.rubberband.setGeometry(QtCore.QRect(event.screenPos(),
                                                     QtCore.QSize()))
            self.rubberband.show()
            return True

        if (event.type() == QtCore.QEvent.GraphicsSceneMouseRelease and
                                    event.button() == QtCore.Qt.LeftButton):
            assert(self.rubberband is not None)
            self.rubberband.hide()
            self.rubberband = None
            rect = QtCore.QRectF(
                            event.buttonDownScenePos(QtCore.Qt.LeftButton),
                            event.scenePos()).normalized()
            item = obj.addEllipse(rect, self.pen, self.brush)
            item.setFlag(QtGui.QGraphicsItem.ItemIsSelectable, True)
            item.setFlag(QtGui.QGraphicsItem.ItemIsMovable, True)
            return True

        elif (event.type() == QtCore.QEvent.GraphicsSceneMouseMove and
                                bool(event.buttons() & QtCore.Qt.LeftButton)):
            assert(self.rubberband is not None)
            rect = QtCore.QRect(
                            event.buttonDownScreenPos(QtCore.Qt.LeftButton),
                            event.screenPos()).normalized()
            self.rubberband.setGeometry(rect)
            return True

        return False