Geografic-Information-System/gui/wxpython/swipe/mapwindow.py

"""!
@package swipe.mapwindow

@brief Map Swipe map window.

Class _MouseEvent taken from wxPython FloatCanvas source code (Christopher Barker).

Classes:
 - mapwindow::SwipeBufferedWindow
 - mapwindow::_MouseEvent

(C) 2012 by the GRASS Development Team

This program is free software under the GNU General Public License
(>=v2). Read the file COPYING that comes with GRASS for details.

@author Anna Kratochvilova <kratochanna gmail.com>
"""

import wx

from core.debug import Debug
from mapdisp.mapwindow import BufferedWindow


EVT_MY_MOUSE_EVENTS = wx.NewEventType()
EVT_MY_MOTION = wx.NewEventType()
EVT_MOUSE_EVENTS = wx.PyEventBinder(EVT_MY_MOUSE_EVENTS)
EVT_MOTION = wx.PyEventBinder(EVT_MY_MOTION)


class SwipeBufferedWindow(BufferedWindow):
    """!A subclass of BufferedWindow class. 

    Enables to draw the image translated.
    Special mouse events with changed coordinates are used.
    """
    def __init__(self, parent, Map, frame,
                 tree = None, lmgr = None, **kwargs):
        BufferedWindow.__init__(self, parent = parent, Map = Map, frame = frame, tree = tree, lmgr = lmgr, **kwargs)
        Debug.msg(2, "SwipeBufferedWindow.__init__()")

        self.specialSize = super(SwipeBufferedWindow, self).GetClientSize()
        self.specialCoords = [0, 0]
        self.imageId = 99
        self.movingSash = False

    def _bindMouseEvents(self):
        """!Binds wx mouse events and custom mouse events"""
        wx.EVT_MOUSE_EVENTS(self, self._mouseActions)
        wx.EVT_MOTION(self, self._mouseMotion)
        self.Bind(EVT_MOTION, self.OnMotion)
        self.Bind(EVT_MOUSE_EVENTS, self.MouseActions)
        self.Bind(wx.EVT_CONTEXT_MENU, self.OnContextMenu)

    def _RaiseMouseEvent(self, Event, EventType):
         """!This is called in various other places to raise a Mouse Event
         """
         Debug.msg(5, "SwipeBufferedWindow._RaiseMouseEvent()")

        # this computes the new coordinates from the mouse coords.
         x, y = Event.GetPosition()
         pt = x - self.GetImageCoords()[0], y - self.GetImageCoords()[1]
         evt = _MouseEvent(EventType, Event, self.GetId(), pt)
         self.GetEventHandler().ProcessEvent(evt)
         # this skip was not in the original code but is needed here
         Event.Skip()

    def _mouseActions(self, event):
        self._RaiseMouseEvent(event, EVT_MY_MOUSE_EVENTS)

    def _mouseMotion(self, event):
        self._RaiseMouseEvent(event, EVT_MY_MOTION)

    def GetClientSize(self):
        """!Overriden method which returns simulated window size.
        """
        return self.specialSize

    def SetClientSize(self, size):
        """!Overriden method which sets simulated window size.
        """
        Debug.msg(3, "SwipeBufferedWindow.SetClientSize(): size = %s" % size)
        self.specialSize = size

    def GetImageCoords(self):
        """!Returns coordinates of rendered image"""
        return self.specialCoords

    def SetImageCoords(self, coords):
        """!Sets coordinates of rendered image"""
        Debug.msg(3, "SwipeBufferedWindow.SetImageCoords(): coords = %s, %s" % (coords[0], coords[1]))
        self.specialCoords = coords

    def OnSize(self, event):
        """!Calls superclass's OnSize method only when needed"""
        Debug.msg(5, "SwipeBufferedWindow.OnSize()")
        if not self.movingSash:
            super(SwipeBufferedWindow, self).OnSize(event)

    def ZoomToMap(self, layers = None, ignoreNulls = False, render = True):
        super(SwipeBufferedWindow, self).ZoomToMap(layers, ignoreNulls, render)
        self.frame.UpdateRegion()

    def ZoomBack(self):
        """!Zoom last (previously stored position)
        """
        super(SwipeBufferedWindow, self).ZoomBack()
        self.frame.UpdateRegion()

    def Draw(self, pdc, img = None, drawid = None, pdctype = 'image', coords = [0, 0, 0, 0]):
        """!Draws image (map) with translated coordinates.
        """
        Debug.msg(2, "SwipeBufferedWindow.Draw()")

        if pdctype == 'image':
            coords = self.GetImageCoords()

        return super(SwipeBufferedWindow, self).Draw(pdc, img, drawid, pdctype, coords)
        
    def TranslateImage(self, dx, dy):
        """!Translate image and redraw.
        """
        Debug.msg(5, "SwipeBufferedWindow.TranslateImage(): dx = %s, dy = %s" % (dx, dy))

        self.pdc.TranslateId(self.imageId, dx, dy)
        self.Refresh()
        

    def MouseActions(self, event):
        """!Handle mouse events and if needed let parent frame know"""
        super(SwipeBufferedWindow, self).MouseActions(event)
        if event.GetWheelRotation() != 0 or \
           event.LeftUp() or \
           event.MiddleUp():

            self.frame.UpdateRegion()

        event.Skip()
        
    def MouseDraw(self, pdc = None, begin = None, end = None):
        """!Overriden method to recompute coordinates back to original values
        so that e.g. drawing of zoom box is done properly"""
        Debug.msg(5, "SwipeBufferedWindow.MouseDraw()")

        offsetX, offsetY = self.GetImageCoords()
        begin = (self.mouse['begin'][0] + offsetX, self.mouse['begin'][1] + offsetY)
        end = (self.mouse['end'][0] + offsetX, self.mouse['end'][1] + offsetY)
        super(SwipeBufferedWindow, self).MouseDraw(pdc, begin, end)


class _MouseEvent(wx.PyCommandEvent):
    """!
    This event class takes a regular wxWindows mouse event as a parameter, 
    and wraps it so that there is access to all the original methods. This 
    is similar to subclassing, but you can't subclass a wxWindows event.

    The goal is to be able to it just like a regular mouse event.

    Difference is that it is a CommandEvent, which propagates up the 
    window hierarchy until it is handled.
    """

    def __init__(self, EventType, NativeEvent, WinID, changed = None):
        Debug.msg(5, "_MouseEvent:__init__()")

        wx.PyCommandEvent.__init__(self)

        self.SetEventType(EventType)
        self._NativeEvent = NativeEvent
        self.changed = changed

    def GetPosition(self):
        return wx.Point(*self.changed)

    def GetPositionTuple(self):
        return self.changed

    def GetX(self):
        return self.changed[0]
        
    def GetY(self):
        return self.changed[1]

    # this delegates all other attributes to the native event.
    def __getattr__(self, name):
        return getattr(self._NativeEvent, name)