Source code for stretch.core

# -*- 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.


'''Core modue for image stretch control.'''


from qt import QtCore, QtGui

from gsdview import qt4support

from .widgets import StretchDialog


__author__ = 'Antonio Valentino <a_valentino@users.sf.net>'
__date__ = '$Date: 2010/02/14 22:02:21 $'
__revision__ = '$Revision: 36b7b35ff3b6 $'


class StretchTool(QtCore.QObject):
    def __init__(self, app, **kwargs):
        super(StretchTool, self).__init__(app, **kwargs)
        self.app = app

        self.dialog = StretchDialog(parent=app)
        self.dialog.hide()

        self.action = self._setupAction()
        self.action.setEnabled(False)

        self.dialog.finished.connect(lambda: self.action.setChecked(False))
        self.app.mdiarea.subWindowActivated.connect(self.onSubWindowChanged)
        #~ self.app.treeview.clicked.connect(self.onItemClicked)
        #~ self.app.subWindowClosed(self.onModelChanged)
        self.dialog.valueChanged.connect(self.onStretchChanged)

        self.toolbar = QtGui.QToolBar(self.tr('Stretching Toolbar'))
        self.toolbar.setObjectName('stretchingToolbar')
        self.toolbar.addAction(self.action)

    def _setupAction(self):
        icon = qt4support.geticon('stretching.svg', __name__)
        action = QtGui.QAction(icon, self.tr('Stretch'), self,
                               objectName='stretchAction',
                               statusTip=self.tr('Stretch'),
                               checkable=True,
                               triggered=self.onButtonToggled)

        return action

    @QtCore.Slot(bool)
    def onButtonToggled(self, checked=True):
        if checked:
            self.reset()
            self.dialog.show()
            #self.action.setChecked(True)
        else:
            self.dialog.hide()
            self.action.setChecked(False)

    def reset(self, item=None):
        if item is None:
            item = self.currentGraphicsItem()
        if item is None or not hasattr(item, 'stretch'):
            self.dialog.setEnabled(False)
            return

        self.dialog.setEnabled(True)

        imin, imax = item.stretch.range
        minimum, maximum = item.dataRange()

        # @TODO: remove this
        #minimum = None

        if minimum is not None:
            self.dialog.stretchwidget.setMinimum(minimum)
        else:
            self.dialog.stretchwidget.setMinimum(min(imin, 0))

        if maximum is not None:
            self.dialog.stretchwidget.setMaximum(maximum)
        else:
            self.dialog.stretchwidget.setMaximum(max(imax, 2 * imax))

        self.dialog.stretchwidget.setLow(imin)
        self.dialog.stretchwidget.setHigh(imax)
        self.dialog.saveState()

    # @TODO: move to main app (??)
    def currentGraphicsItem(self, window=None):
        if window is None:
            window = self.app.mdiarea.activeSubWindow()
        try:
            return window.item.graphicsitem
        except AttributeError:
            return None

    @QtCore.Slot()
    @QtCore.Slot(QtGui.QMdiSubWindow)
    def onSubWindowChanged(self, subwin=None):
        if subwin is None:
            subwin = self.app.mdiarea.activeSubWindow()

        if subwin is None:
            self.action.setEnabled(self.dialog.isVisible())
            self.dialog.setEnabled(False)
            return

        item = self.currentGraphicsItem(subwin)
        try:
            stretchable = item.stretch is not None
        except AttributeError:
            stretchable = False

        if stretchable:
            self.action.setEnabled(True)
            if self.dialog.isVisible():
                self.dialog.setEnabled(True)
                self.reset(item)
        else:
            if self.dialog.isVisible():
                self.action.setEnabled(True)
                self.dialog.setEnabled(False)
            else:
                self.action.setEnabled(False)

    # @TODO: remove
    #~ @QtCore.Slot(QtCore.QModelIndex)
    #~ def onItemClicked(self, index):
        #~ if not self.app.mdiarea.activeSubWindow():
            #~ item = self.app.datamodel.itemFromIndex(index)
            #~ self.reset(item)

    #~ @QtCore.Slot()
    #~ @QtCore.Slot(QtCore.QModelIndex, int, int)
    #~ def onModelChanged(self, index=None, start=None, stop=None):
        #~ item = self.app.currentGraphicsItem()
        #~ self.reset(item)

    @QtCore.Slot()
    def onStretchChanged(self):
        item = self.currentGraphicsItem()
        try:
            stretch = item.stretch
        except AttributeError:
            #self.dialog.hide()
            pass
        else:
            vmin, vmax = self.dialog.values()
            stretch.set_range(vmin, vmax)
            item.update()