Fixed database typo and removed unnecessary class identifier.

venv/Lib/site-packages/skimage/viewer/utils/canvas.py

@@ -0,0 +1,106 @@
+
+
+class BlitManager(object):
+
+    """Object that manages blits on an axes"""
+
+    def __init__(self, ax):
+        self.ax = ax
+        self.canvas = ax.figure.canvas
+        self.canvas.mpl_connect('draw_event', self.on_draw_event)
+        self.ax = ax
+        self.background = None
+        self.artists = []
+
+    def add_artists(self, artists):
+        self.artists.extend(artists)
+        self.redraw()
+
+    def remove_artists(self, artists):
+        for artist in artists:
+            self.artists.remove(artist)
+
+    def on_draw_event(self, event=None):
+        self.background = self.canvas.copy_from_bbox(self.ax.bbox)
+        self.draw_artists()
+
+    def redraw(self):
+        if self.background is not None:
+            self.canvas.restore_region(self.background)
+            self.draw_artists()
+            self.canvas.blit(self.ax.bbox)
+        else:
+            self.canvas.draw_idle()
+
+    def draw_artists(self):
+        for artist in self.artists:
+            self.ax.draw_artist(artist)
+
+
+class EventManager(object):
+
+    """Object that manages events on a canvas"""
+
+    def __init__(self, ax):
+        self.canvas = ax.figure.canvas
+        self.connect_event('button_press_event', self.on_mouse_press)
+        self.connect_event('key_press_event', self.on_key_press)
+        self.connect_event('button_release_event', self.on_mouse_release)
+        self.connect_event('motion_notify_event', self.on_move)
+        self.connect_event('scroll_event', self.on_scroll)
+
+        self.tools = []
+        self.active_tool = None
+
+    def connect_event(self, name, handler):
+        self.canvas.mpl_connect(name, handler)
+
+    def attach(self, tool):
+        self.tools.append(tool)
+        self.active_tool = tool
+
+    def detach(self, tool):
+        self.tools.remove(tool)
+        if self.tools:
+            self.active_tool = self.tools[-1]
+        else:
+            self.active_tool = None
+
+    def on_mouse_press(self, event):
+        for tool in self.tools:
+            if not tool.ignore(event) and tool.hit_test(event):
+                self.active_tool = tool
+                break
+        if self.active_tool and not self.active_tool.ignore(event):
+            self.active_tool.on_mouse_press(event)
+            return
+        for tool in reversed(self.tools):
+            if not tool.ignore(event):
+                self.active_tool = tool
+                tool.on_mouse_press(event)
+                return
+
+    def on_key_press(self, event):
+        tool = self._get_tool(event)
+        if tool is not None:
+            tool.on_key_press(event)
+
+    def _get_tool(self, event):
+        if not self.tools or self.active_tool.ignore(event):
+            return None
+        return self.active_tool
+
+    def on_mouse_release(self, event):
+        tool = self._get_tool(event)
+        if tool is not None:
+            tool.on_mouse_release(event)
+
+    def on_move(self, event):
+        tool = self._get_tool(event)
+        if tool is not None:
+            tool.on_move(event)
+
+    def on_scroll(self, event):
+        tool = self._get_tool(event)
+        if tool is not None:
+            tool.on_scroll(event)