Merge pull request matplotlib#17102 from anntzer/tkactions

Switch tk pan/zoom to use togglable buttons.

Author: QuLogic

lib/matplotlib/backends/_backend_tk.py

@@ -521,12 +521,23 @@ def set_cursor(self, cursor):
         window.configure(cursor=cursord[cursor])
         window.update_idletasks()
 
-    def _Button(self, text, file, command, extension='.gif'):
-        img_file = str(cbook._get_data_path('images', file + extension))
-        im = tk.PhotoImage(master=self, file=img_file)
-        b = tk.Button(
-            master=self, text=text, padx=2, pady=2, image=im, command=command)
-        b._ntimage = im
+    def _Button(self, text, image_file, toggle, command):
+        image = (tk.PhotoImage(master=self, file=image_file)
+                 if image_file is not None else None)
+        if not toggle:
+            b = tk.Button(master=self, text=text, image=image, command=command)
+        else:
+            # There is a bug in tkinter included in some python 3.6 versions
+            # that without this variable, produces a "visual" toggling of
+            # other near checkbuttons
+            # https://bugs.python.org/issue29402
+            # https://bugs.python.org/issue25684
+            var = tk.IntVar()
+            b = tk.Checkbutton(
+                master=self, text=text, image=image, command=command,
+                indicatoron=False, variable=var)
+            b.var = var
+        b._ntimage = image
         b.pack(side=tk.LEFT)
         return b
 
@@ -546,20 +557,42 @@ def _init_toolbar(self):
 
         self.update()  # Make axes menu
 
+        self._buttons = {}
         for text, tooltip_text, image_file, callback in self.toolitems:
             if text is None:
                 # Add a spacer; return value is unused.
                 self._Spacer()
             else:
-                button = self._Button(text=text, file=image_file,
-                                      command=getattr(self, callback))
+                self._buttons[text] = button = self._Button(
+                    text,
+                    str(cbook._get_data_path(f"images/{image_file}.gif")),
+                    toggle=callback in ["zoom", "pan"],
+                    command=getattr(self, callback),
+                )
                 if tooltip_text is not None:
                     ToolTip.createToolTip(button, tooltip_text)
 
         self.message = tk.StringVar(master=self)
         self._message_label = tk.Label(master=self, textvariable=self.message)
         self._message_label.pack(side=tk.RIGHT)
 
+    def _update_buttons_checked(self):
+        for name, mode in [("Pan", "PAN"), ("Zoom", "ZOOM")]:
+            button = self._buttons.get(name)
+            if button:
+                if self.mode.name == mode and not button.var.get():
+                    button.select()
+                elif self.mode.name != mode and button.var.get():
+                    button.deselect()
+
+    def pan(self, *args):
+        super().pan(*args)
+        self._update_buttons_checked()
+
+    def zoom(self, *args):
+        super().zoom(*args)
+        self._update_buttons_checked()
+
     def configure_subplots(self):
         toolfig = Figure(figsize=(6, 3))
         window = tk.Toplevel()
@@ -700,7 +733,8 @@ def __init__(self, toolmanager, window):
     def add_toolitem(
             self, name, group, position, image_file, description, toggle):
         frame = self._get_groupframe(group)
-        button = self._Button(name, image_file, toggle, frame)
+        button = NavigationToolbar2Tk._Button(self, name, image_file, toggle,
+                                              lambda: self._button_click(name))
         if description is not None:
             ToolTip.createToolTip(button, description)
         self._toolitems.setdefault(name, [])
@@ -719,30 +753,6 @@ def _add_separator(self):
         separator = tk.Frame(master=self, bd=5, width=1, bg='black')
         separator.pack(side=tk.LEFT, fill=tk.Y, padx=2)
 
-    def _Button(self, text, image_file, toggle, frame):
-        if image_file is not None:
-            im = tk.PhotoImage(master=self, file=image_file)
-        else:
-            im = None
-
-        if not toggle:
-            b = tk.Button(master=frame, text=text, padx=2, pady=2, image=im,
-                          command=lambda: self._button_click(text))
-        else:
-            # There is a bug in tkinter included in some python 3.6 versions
-            # that without this variable, produces a "visual" toggling of
-            # other near checkbuttons
-            # https://bugs.python.org/issue29402
-            # https://bugs.python.org/issue25684
-            var = tk.IntVar()
-            b = tk.Checkbutton(master=frame, text=text, padx=2, pady=2,
-                               image=im, indicatoron=False,
-                               command=lambda: self._button_click(text),
-                               variable=var)
-        b._ntimage = im
-        b.pack(side=tk.LEFT)
-        return b
-
     def _button_click(self, name):
         self.trigger_tool(name)