factored out default mpl key handling so user interface code could access it; illustrate in gtk, tk and qt examples

Author: jdh2358

examples/user_interfaces/embedding_in_gtk2.py

@@ -17,6 +17,8 @@
 #from matplotlib.backends.backend_gtk import NavigationToolbar2GTK as NavigationToolbar
 from matplotlib.backends.backend_gtkagg import NavigationToolbar2GTKAgg as NavigationToolbar
 
+# implement the default mpl key bindings
+from matplotlib.backend_bases import key_press_handler
 
 win = gtk.Window()
 win.connect("destroy", lambda x: gtk.main_quit())
@@ -40,5 +42,11 @@
 vbox.pack_start(toolbar, False, False)
 
 
+def on_key_event(event):
+    print('you pressed %s'%event.key)
+    key_press_handler(event, canvas, toolbar)
+
+canvas.mpl_connect('key_press_event', on_key_event)
+
 win.show_all()
 gtk.main()

examples/user_interfaces/embedding_in_qt4_wtoolbar.py

@@ -0,0 +1,63 @@
+import sys
+import numpy as np
+from matplotlib.figure import Figure
+from matplotlib.backend_bases import FigureManagerBase, key_press_handler
+from PyQt4.QtCore import *
+from PyQt4.QtGui import *
+
+from matplotlib.backends.backend_qt4agg import FigureCanvasQTAgg as FigureCanvas
+from matplotlib.backends.backend_qt4agg import NavigationToolbar2QTAgg as NavigationToolbar
+
+
+class AppForm(QMainWindow):
+    def __init__(self, parent=None):
+        QMainWindow.__init__(self, parent)
+        #self.x, self.y = self.get_data()
+        self.data = self.get_data2()
+        self.create_main_frame()
+        self.on_draw()
+
+    def create_main_frame(self):
+        self.main_frame = QWidget()
+
+        self.fig = Figure((5.0, 4.0), dpi=100)
+        self.canvas = FigureCanvas(self.fig)
+        self.canvas.setParent(self.main_frame)
+        self.canvas.setFocusPolicy( Qt.ClickFocus )
+        self.canvas.setFocus()
+
+        self.mpl_toolbar = NavigationToolbar(self.canvas, self.main_frame)
+
+        self.canvas.mpl_connect('key_press_event', self.on_key_press)
+
+        vbox = QVBoxLayout()
+        vbox.addWidget(self.canvas)         # the matplotlib canvas
+        vbox.addWidget(self.mpl_toolbar)
+        self.main_frame.setLayout(vbox)
+        self.setCentralWidget(self.main_frame)
+
+    def get_data2(self):
+        return np.arange(20).reshape([4,5]).copy()
+
+    def on_draw(self):
+        self.fig.clear()
+        self.axes = self.fig.add_subplot(111)
+        #self.axes.plot(self.x, self.y, 'ro')
+        #self.axes.imshow(self.data, interpolation='nearest')
+        self.axes.plot([1,2,3])
+        self.canvas.draw()
+
+    def on_key_press(self, event):
+        print 'you pressed', event.key
+        # implement the default mpl key press events described at
+        # http://matplotlib.sourceforge.net/users/navigation_toolbar.html#navigation-keyboard-shortcuts
+        key_press_handler(event, self.canvas, self.mpl_toolbar)
+
+def main():
+    app = QApplication(sys.argv)
+    form = AppForm()
+    form.show()
+    app.exec_()
+
+if __name__ == "__main__":
+    main()

examples/user_interfaces/embedding_in_tk.py

@@ -5,6 +5,10 @@
 
 from numpy import arange, sin, pi
 from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg, NavigationToolbar2TkAgg
+# implement the default mpl key bindings
+from matplotlib.backend_bases import key_press_handler
+
+
 from matplotlib.figure import Figure
 
 import sys
@@ -34,6 +38,12 @@
 toolbar.update()
 canvas._tkcanvas.pack(side=Tk.TOP, fill=Tk.BOTH, expand=1)
 
+def on_key_event(event):
+    print('you pressed %s'%event.key)
+    key_press_handler(event, canvas, toolbar)
+
+canvas.mpl_connect('key_press_event', on_key_event)
+
 def _quit():
     root.quit()     # stops mainloop
     root.destroy()  # this is necessary on Windows to prevent

lib/matplotlib/backend_bases.py

@@ -1436,7 +1436,7 @@ def __init__(self, figure):
         self.button_pick_id = self.mpl_connect('button_press_event',self.pick)
         self.scroll_pick_id = self.mpl_connect('scroll_event',self.pick)
         self.mouse_grabber = None # the axes currently grabbing mouse
-
+        self.toolbar = None  # NavigationToolbar2 will set me
         if False:
             ## highlight the artists that are hit
             self.mpl_connect('motion_notify_event',self.onHilite)
@@ -2213,6 +2213,110 @@ def stop_event_loop_default(self):
         self._looping = False
 
 
+def key_press_handler(event, canvas, toolbar=None):
+    """
+    Implement the default mpl key bindings for the canvas and toolbar
+    described at :ref:`navigation-keyboard-shortcuts`
+
+    *event*
+      a :class:`KeyEvent` instance
+    *canvas*
+      a :class:`FigureCanvasBase` instance
+    *toolbar*
+      a class:`NavigationToolbar2` instance
+
+    """
+    # these bindings happen whether you are over an axes or not
+    #if event.key == 'q':
+    #    self.destroy() # how cruel to have to destroy oneself!
+    #    return
+
+    if event.key is None:
+        return
+
+    # Load key-mappings from your matplotlibrc file.
+    fullscreen_keys = rcParams['keymap.fullscreen']
+    home_keys = rcParams['keymap.home']
+    back_keys = rcParams['keymap.back']
+    forward_keys = rcParams['keymap.forward']
+    pan_keys = rcParams['keymap.pan']
+    zoom_keys = rcParams['keymap.zoom']
+    save_keys = rcParams['keymap.save']
+    grid_keys = rcParams['keymap.grid']
+    toggle_yscale_keys = rcParams['keymap.yscale']
+    toggle_xscale_keys = rcParams['keymap.xscale']
+    all = rcParams['keymap.all_axes']
+
+    # toggle fullscreen mode (default key 'f')
+    if event.key in fullscreen_keys:
+        self.full_screen_toggle()
+
+    if toolbar is not None:
+        # home or reset mnemonic  (default key 'h', 'home' and 'r')
+        if event.key in home_keys:
+            toolbar.home()
+        # forward / backward keys to enable left handed quick navigation
+        # (default key for backward: 'left', 'backspace' and 'c')
+        elif event.key in back_keys:
+            toolbar.back()
+        # (default key for forward: 'right' and 'v')
+        elif event.key in forward_keys:
+            toolbar.forward()
+        # pan mnemonic (default key 'p')
+        elif event.key in pan_keys:
+            toolbar.pan()
+        # zoom mnemonic (default key 'o')
+        elif event.key in zoom_keys:
+            toolbar.zoom()
+        # saving current figure (default key 's')
+        elif event.key in save_keys:
+            toolbar.save_figure()
+
+    if event.inaxes is None:
+        return
+
+    # the mouse has to be over an axes to trigger these
+    # switching on/off a grid in current axes (default key 'g')
+    if event.key in grid_keys:
+        event.inaxes.grid()
+        canvas.draw()
+    # toggle scaling of y-axes between 'log and 'linear' (default key 'l')
+    elif event.key in toggle_yscale_keys:
+        ax = event.inaxes
+        scale = ax.get_yscale()
+        if scale == 'log':
+            ax.set_yscale('linear')
+            ax.figure.canvas.draw()
+        elif scale == 'linear':
+            ax.set_yscale('log')
+            ax.figure.canvas.draw()
+    # toggle scaling of x-axes between 'log and 'linear' (default key 'k')
+    elif event.key in toggle_xscale_keys:
+        ax = event.inaxes
+        scalex = ax.get_xscale()
+        if scalex == 'log':
+            ax.set_xscale('linear')
+            ax.figure.canvas.draw()
+        elif scalex == 'linear':
+            ax.set_xscale('log')
+            ax.figure.canvas.draw()
+
+    elif (event.key.isdigit() and event.key!='0') or event.key in all:
+        # keys in list 'all' enables all axes (default key 'a'),
+        # otherwise if key is a number only enable this particular axes
+        # if it was the axes, where the event was raised
+        if not (event.key in all):
+            n = int(event.key)-1
+        for i, a in enumerate(canvas.figure.get_axes()):
+            # consider axes, in which the event was raised
+            # FIXME: Why only this axes?
+            if event.x is not None and event.y is not None \
+                   and a.in_axes(event):
+                if event.key in all:
+                    a.set_navigate(True)
+                else:
+                    a.set_navigate(i==n)
+
 
 class FigureManagerBase:
     """
@@ -2244,97 +2348,11 @@ def resize(self, w, h):
         pass
 
     def key_press(self, event):
-
-        # these bindings happen whether you are over an axes or not
-        #if event.key == 'q':
-        #    self.destroy() # how cruel to have to destroy oneself!
-        #    return
-
-        if event.key is None:
-            return
-
-        # Load key-mappings from your matplotlibrc file.
-        fullscreen_keys = rcParams['keymap.fullscreen']
-        home_keys = rcParams['keymap.home']
-        back_keys = rcParams['keymap.back']
-        forward_keys = rcParams['keymap.forward']
-        pan_keys = rcParams['keymap.pan']
-        zoom_keys = rcParams['keymap.zoom']
-        save_keys = rcParams['keymap.save']
-        grid_keys = rcParams['keymap.grid']
-        toggle_yscale_keys = rcParams['keymap.yscale']
-        toggle_xscale_keys = rcParams['keymap.xscale']
-        all = rcParams['keymap.all_axes']
-
-        # toggle fullscreen mode (default key 'f')
-        if event.key in fullscreen_keys:
-            self.full_screen_toggle()
-
-        # home or reset mnemonic  (default key 'h', 'home' and 'r')
-        elif event.key in home_keys:
-            self.canvas.toolbar.home()
-        # forward / backward keys to enable left handed quick navigation
-        # (default key for backward: 'left', 'backspace' and 'c')
-        elif event.key in back_keys:
-            self.canvas.toolbar.back()
-        # (default key for forward: 'right' and 'v')
-        elif event.key in forward_keys:
-            self.canvas.toolbar.forward()
-        # pan mnemonic (default key 'p')
-        elif event.key in pan_keys:
-            self.canvas.toolbar.pan()
-        # zoom mnemonic (default key 'o')
-        elif event.key in zoom_keys:
-            self.canvas.toolbar.zoom()
-        # saving current figure (default key 's')
-        elif event.key in save_keys:
-            self.canvas.toolbar.save_figure()
-
-        if event.inaxes is None:
-            return
-
-        # the mouse has to be over an axes to trigger these
-        # switching on/off a grid in current axes (default key 'g')
-        if event.key in grid_keys:
-            event.inaxes.grid()
-            self.canvas.draw()
-        # toggle scaling of y-axes between 'log and 'linear' (default key 'l')
-        elif event.key in toggle_yscale_keys:
-            ax = event.inaxes
-            scale = ax.get_yscale()
-            if scale == 'log':
-                ax.set_yscale('linear')
-                ax.figure.canvas.draw()
-            elif scale == 'linear':
-                ax.set_yscale('log')
-                ax.figure.canvas.draw()
-        # toggle scaling of x-axes between 'log and 'linear' (default key 'k')
-        elif event.key in toggle_xscale_keys:
-            ax = event.inaxes
-            scalex = ax.get_xscale()
-            if scalex == 'log':
-                ax.set_xscale('linear')
-                ax.figure.canvas.draw()
-            elif scalex == 'linear':
-                ax.set_xscale('log')
-                ax.figure.canvas.draw()
-
-        elif (event.key.isdigit() and event.key!='0') or event.key in all:
-            # keys in list 'all' enables all axes (default key 'a'),
-            # otherwise if key is a number only enable this particular axes
-            # if it was the axes, where the event was raised
-            if not (event.key in all):
-                n = int(event.key)-1
-            for i, a in enumerate(self.canvas.figure.get_axes()):
-                # consider axes, in which the event was raised
-                # FIXME: Why only this axes?
-                if event.x is not None and event.y is not None \
-                       and a.in_axes(event):
-                    if event.key in all:
-                        a.set_navigate(True)
-                    else:
-                        a.set_navigate(i==n)
-
+        """
+        implement the default mpl key bindings defined at
+        :ref:`navigation-keyboard-shortcuts`
+        """
+        key_press_handler(event, self.canvas, self.canvas.toolbar)
 
     def show_popup(self, msg):
         """