Added a text box example: evaluates any string inputs as y(x).

matplotlib · tacaswell · Sep 3, 2016 · Oct 27, 2015 · Oct 31, 2015 · Jan 20, 2016
commit e70217b1263ea6b00593adb4012c8a0b2e8cf248
diff --git a/doc/users/whats_new.rst b/doc/users/whats_new.rst
@@ -1,4 +1,4 @@
-w.. _whats-new:
+.. _whats-new:
 
 ************************
 What's new in matplotlib
@@ -245,8 +245,8 @@ Widgets
 -------
 
 Added TextBox Widget
-
 ````````````````````
+
 Added a widget that allows text entry by reading key events when it is active. 
 Text caret in text box is visible when it is active, can be moved using arrow keys but not mouse
 

diff --git a/examples/widgets/textbox.py b/examples/widgets/textbox.py
@@ -0,0 +1,23 @@
+
+import numpy as np
+import matplotlib.pyplot as plt
+from matplotlib.widgets import TextBox
+fig, ax = plt.subplots()
+plt.subplots_adjust(bottom=0.2)
+t = np.arange(-2.0, 2.0, 0.001)
+s = t ** 2
+initial_text = "t ** 2"
+l, = plt.plot(t, s, lw=2)
+
+
+def submit(text):
+    ydata = eval(text)
+    l.set_ydata(ydata)
+    ax.set_ylim(np.min(ydata), np.max(ydata))
+    plt.draw()
+
+axbox = plt.axes([0.1, 0.05, 0.8, 0.075])
+text_box = TextBox(axbox, 'Evaluate', initial=initial_text)
+text_box.on_submit(submit)
+
+plt.show()
diff --git a/lib/matplotlib/widgets.py b/lib/matplotlib/widgets.py
@@ -628,14 +628,14 @@ def disconnect(self, cid):
         except KeyError:
             pass
 
+
 class TextBox(AxesWidget):
     """
     A GUI neutral text input box.
 
-    For the text box to remain responsive
-    you must keep a reference to it.
+    For the text box to remain responsive you must keep a reference to it.
 
-    The following attributes are accessible
+    The following attributes are accessible:
 
       *ax*
         The :class:`matplotlib.axes.Axes` the button renders into.
@@ -649,11 +649,13 @@ class TextBox(AxesWidget):
       *hovercolor*
         The color of the text box when hovering.
 
-    Call :meth:`on_text_change` to be updated whenever the text changes
-    Call :meth:`on_submit` to be updated whenever the user hits enter or leaves the text entry field
+    Call :meth:`on_text_change` to be updated whenever the text changes.
+
+    Call :meth:`on_submit` to be updated whenever the user hits enter or
+    leaves the text entry field.
     """
 
-    def __init__(self, ax, label, initial = '', 
+    def __init__(self, ax, label, initial='',
                  color='.95', hovercolor='1'):
         """
         Parameters
@@ -664,48 +666,48 @@ def __init__(self, ax, label, initial = '',
 
         label : str
             Label for this text box. Accepts string.
-        
+
         initial : str
             Initial value in the text box
-            
+
         color : color
             The color of the box
 
         hovercolor : color
             The color of the box when the mouse is over it
         """
         AxesWidget.__init__(self, ax)
-        
-        self.DIST_FROM_LEFT = .05        
-        
+
+        self.DIST_FROM_LEFT = .05
+
         self.params_to_disable = []
-        for key in rcParams.keys():                   
+        for key in rcParams.keys():
             if u'keymap' in key:
-               self.params_to_disable += [key]
-        
+                self.params_to_disable += [key]
+
         self.text = initial
-
-
-
-
-        self.label = ax.text(0.0,0.5, label,
+        self.label = ax.text(0.0, 0.5, label,
                              verticalalignment='center',
                              horizontalalignment='right',
                              transform=ax.transAxes)
         self.text_disp = self._make_text_disp(self.text)
-        
+
         self.cnt = 0
         self.change_observers = {}
         self.submit_observers = {}
-
-        self.ax.set_xlim(0, 1)      #If these lines are removed, the cursor won't appear 
-        self.ax.set_ylim(0, 1)      #the first time the box is clicked
-
-        self.cursor_index = 0;
-        self.cursor = self.ax.vlines(0, 0, 0)    #because this is initialized, _render_cursor 
-        self.cursor.set_visible(False)           #can assume that cursor exists
-
-
+
+        # If these lines are removed, the cursor won't appear the first
+        # time the box is clicked:
+        self.ax.set_xlim(0, 1)
+        self.ax.set_ylim(0, 1)
+
+        self.cursor_index = 0
+
+        # Because this is initialized, _render_cursor
+        # can assume that cursor exists.
+        self.cursor = self.ax.vlines(0, 0, 0)
+        self.cursor.set_visible(False)
+
         self.connect_event('button_press_event', self._click)
         self.connect_event('button_release_event', self._release)
         self.connect_event('motion_notify_event', self._motion)
@@ -718,110 +720,107 @@ def __init__(self, ax, label, initial = '',
         self.hovercolor = hovercolor
 
         self._lastcolor = color
-
-        self.capturekeystrokes = False        
-
-
 
-
+        self.capturekeystrokes = False
+
     def _make_text_disp(self, string):
         return self.ax.text(self.DIST_FROM_LEFT, 0.5, string,
-                             verticalalignment='center',
-              
EDBE
               horizontalalignment='left',
-                             transform=self.ax.transAxes)
+                            verticalalignment='center',
+                            horizontalalignment='left',
+                            transform=self.ax.transAxes)
+
     def _rendercursor(self):
-        #this is a hack to figure out where the cursor should go.
-        #we draw the text up to where the cursor should go, measure 
-        #save its dimensions, draw the real text, then put the cursor
-        #at the saved dimensions
-        
+        # this is a hack to figure out where the cursor should go.
+        # we draw the text up to where the cursor should go, measure
+        # save its dimensions, draw the real text, then put the cursor
+        # at the saved dimensions
+
         widthtext = self.text[:self.cursor_index]
         no_text = False
         if(widthtext == "" or widthtext == " " or widthtext == "  "):
             no_text = widthtext == ""
             widthtext = ","
-
-
+
         wt_disp = self._make_text_disp(widthtext)
-        
+
         self.ax.figure.canvas.draw()
         bb = wt_disp.get_window_extent()
         inv = self.ax.transData.inverted()
         bb = inv.transform(bb)
         wt_disp.set_visible(False)
         if no_text:
-            bb[1, 0] = bb[0, 0]        
-        #hack done
+            bb[1, 0] = bb[0, 0]
+        # hack done
         self.cursor.set_visible(False)
-
-
+
         self.cursor = self.ax.vlines(bb[1, 0], bb[0, 1], bb[1, 1])
         self.ax.figure.canvas.draw()
 
     def _notify_submit_observers(self):
         for cid, func in six.iteritems(self.submit_observers):
                 func(self.text)
-                
+
     def _release(self, event):
         if self.ignore(event):
             return
         if event.canvas.mouse_grabber != self.ax:
             return
         event.canvas.release_mouse(self.ax)
-        
+
     def _keypress(self, event):
         if self.ignore(event):
             return
         if self.capturekeystrokes:
             key = event.key
-            
+
             if(len(key) == 1):
-               self.text = (self.text[:self.cursor_index] + key + 
-                            self.text[self.cursor_index:])
-               self.cursor_index += 1
+                self.text = (self.text[:self.cursor_index] + key +
+                             self.text[self.cursor_index:])
+                self.cursor_index += 1
             elif key == "right":
-               if self.cursor_index != len(self.text):
-                   self.cursor_index += 1
+                if self.cursor_index != len(self.text):
+                    self.cursor_index += 1
             elif key == "left":
-               if self.cursor_index != 0:
-                   self.cursor_index -= 1
+                if self.cursor_index != 0:
+                    self.cursor_index -= 1
             elif key == "home":
-               self.cursor_index = 0
+                self.cursor_index = 0
             elif key == "end":
-               self.cursor_index = len(self.text)
+                self.cursor_index = len(self.text)
             elif(key == "backspace"):
                 if self.cursor_index != 0:
-                    self.text = (self.text[:self.cursor_index - 1] + 
-                        self.text[self.cursor_index:])
+                    self.text = (self.text[:self.cursor_index - 1] +
+                                 self.text[self.cursor_index:])
                     self.cursor_index -= 1
             elif(key == "delete"):
                 if self.cursor_index != len(self.text):
-                    self.text = (self.text[:self.cursor_index] + 
-                        self.text[self.cursor_index + 1:]
1E0A
)
+                    self.text = (self.text[:self.cursor_index] +
+                                 self.text[self.cursor_index + 1:])
+
             self.text_disp.remove()
             self.text_disp = self._make_text_disp(self.text)
             self._rendercursor()
             for cid, func in six.iteritems(self.change_observers):
                 func(self.text)
             if key == "enter":
-                self._notify_submit_observers()       
-        
+                self._notify_submit_observers()
+
     def _click(self, event):
         if self.ignore(event):
             return
         if event.inaxes != self.ax:
-            notifysubmit = False    
-            #because _notify_submit_users might throw an error in the 
-            #user's code, we only want to call it once we've already done
-            #our cleanup.
+            notifysubmit = False
+            # because _notify_submit_users might throw an error in the
+            # user's code, we only want to call it once we've already done
+            # our cleanup.
             if self.capturekeystrokes:
-               for key in self.params_to_disable:
+                for key in self.params_to_disable:
                     rcParams[key] = self.reset_params[key]
-               notifysubmit = True
+                notifysubmit = True
             self.capturekeystrokes = False
             self.cursor.set_visible(False)
             self.ax.figure.canvas.draw()
-            
+
             if notifysubmit:
                 self._notify_submit_observers()
             return
@@ -838,7 +837,6 @@ def _click(self, event):
             self.cursor_index = len(self.text)
             self._rendercursor()
 
-
     def _motion(self, event):
         if self.ignore(event):
             return
@@ -854,31 +852,35 @@ def _motion(self, event):
 
     def on_text_change(self, func):
         """
-        When the text changes, call this *func* with event
+        When the text changes, call this *func* with event.
 
-        A connection id is returned which can be used to disconnect
+        A connection id is returned which can be used to disconnect.
         """
         cid = self.cnt
         self.change_observers[cid] = func
         self.cnt += 1
         return cid
+
     def on_submit(self, func):
         """
-        When the user hits enter or leaves the submision box, call this *func* with event
+        When the user hits enter or leaves the submision box, call this
+        *func* with event.
 
-        A connection id is returned which can be used to disconnect
+        A connection id is returned which can be used to disconnect.
         """
         cid = self.cnt
         self.submit_observers[cid] = func
         self.cnt += 1
         return cid
+
     def disconnect(self, cid):
         """remove the observer with connection id *cid*"""
         try:
             del self.observers[cid]
         except KeyError:
             pass
 
+
 class RadioButtons(AxesWidget):
     """
     A GUI neutral radio button.
@@ -1176,7 +1178,6 @@ def funchspace(self, val):
             self.targetfig.canvas.draw()
 
 
-
 class Cursor(AxesWidget):
     """
     A horizontal and vertical line that spans the axes and moves with