some minor changes for the legend

leejjoon · leejjoon · commit c6e579d49761 · 2008-12-05T00:06:26.000Z
svn path=/trunk/matplotlib/; revision=6494
diff --git a/CHANGELOG b/CHANGELOG
@@ -1,3 +1,7 @@
+2008-12-04 Added fancybox keyword to legend. Also applied some changes
+	   for better look, including baseline adjustment of the
+	   multiline texts so that it is center aligned. -JJL
+
 2008-12-02 The transmuter classes in the patches.py are reorganized as
            subclasses of the Style classes. A few more box and arrow 
 	   styles are added. -JJL
diff --git a/examples/pylab_examples/legend_demo3.py b/examples/pylab_examples/legend_demo3.py
@@ -2,6 +2,7 @@
 
 import matplotlib.pyplot as plt
 import numpy as np
+import pylab
 
 def myplot(ax):
     t1 = np.arange(0.0, 1.0, 0.1)
@@ -21,7 +22,7 @@ def myplot(ax):
 
 ax3 = plt.subplot(3,1,3)
 myplot(ax3)
-ax3.legend(loc=1, ncol=4, mode="expand", shadow=True)
+ax3.legend(loc=1, ncol=4, mode="expand", fancybox=False, shadow=True)
 
 
 #title('Damped oscillation')
diff --git a/lib/matplotlib/legend.py b/lib/matplotlib/legend.py
@@ -113,6 +113,7 @@ def __init__(self, parent, handles, labels,
                  ncol=1, # number of columns
                  mode=None, # mode for horizontal distribution of columns. None, "expand"
 
+                 fancybox=True,
                  shadow = None,
                  ):
         """
@@ -130,6 +131,7 @@ def __init__(self, parent, handles, labels,
         numpoints          the number of points in the legend line
         prop               the font property
         markerscale        the relative size of legend markers vs. original
+        fancybox           if True, draw a frame with a round fancybox.
         shadow             if True, draw a shadow behind legend
         scatteryoffsets    a list of yoffsets for scatter symbols in legend
 
@@ -263,8 +265,11 @@ def __init__(self, parent, handles, labels,
         # The width and height of the legendPatch will be set (in the
         # draw()) to the length that includes the padding. Thus we set
         # pad=0 here.
-        self.legendPatch.set_boxstyle("round",pad=0, #self.borderpad,
-                                      rounding_size=0.2)
+        if fancybox == True:
+            self.legendPatch.set_boxstyle("round",pad=0,
+                                          rounding_size=0.2)
+        else:
+            self.legendPatch.set_boxstyle("square",pad=0)
 
         self._set_artist_props(self.legendPatch)
 
@@ -378,7 +383,8 @@ def _init_legend_box(self, handles, labels):
         labelboxes = []
 
         for l in labels:
-            textbox = TextArea(l, textprops=label_prop)
+            textbox = TextArea(l, textprops=label_prop
+                               multilinebaseline=True, minimumdescent=True)
             text_list.append(textbox._text)
             labelboxes.append(textbox)
 
@@ -387,8 +393,8 @@ def _init_legend_box(self, handles, labels):
 
         # The approximate height and descent of text. These values are
         # only used for plotting the legend handle.
-        height = self._approx_text_height() * 0.6
-        descent = 0. #height/6.
+        height = self._approx_text_height() * 0.7
+        descent = 0. 
 
         # each handle needs to be drawn inside a box of
         # (x, y, w, h) = (0, -descent, width, height).
@@ -440,9 +446,9 @@ def _init_legend_box(self, handles, labels):
                 legline._legmarker = legline_marker
 
             elif isinstance(handle, Patch):
-                p = Rectangle(xy=(0, -0.*descent),
+                p = Rectangle(xy=(0., 0.),
                               width = self.handlelength*self.fontsize,
-                              height=0.*descent+(height-descent)*.9,
+                              height=(height-descent),
                               )
                 p.update_from(handle)
                 self._set_artist_props(p)
@@ -513,19 +519,21 @@ def _init_legend_box(self, handles, labels):
         num_smallcol = self._ncol-num_largecol
 
         # starting index of each column and number of rows in it.
-        largecol = zip(range(0, num_largecol*(nrows+1), (nrows+1)),
-                       [nrows+1] * num_largecol)
-        smallcol = zip(range(num_largecol*(nrows+1), len(handleboxes), nrows),
-                       [nrows] * num_smallcol)
+        largecol = safezip(range(0, num_largecol*(nrows+1), (nrows+1)),
+                           [nrows+1] * num_largecol)
+        smallcol = safezip(range(num_largecol*(nrows+1), len(handleboxes), nrows),
+                           [nrows] * num_smallcol)
 
-        handle_label = zip(handleboxes, labelboxes)
+        handle_label = safezip(handleboxes, labelboxes)
         columnbox = []
         for i0, di in largecol+smallcol:
             # pack handleBox and labelBox into itemBox
             itemBoxes = [HPacker(pad=0,
                                     sep=self.handletextpad*self.fontsize,
                                     children=[h, t], align="baseline")
                          for h, t in handle_label[i0:i0+di]]
+            # minimumdescent=False for the text of the last row of the column
+            itemBoxes[-1].get_children()[1].set_minimumdescent(False)
             
             # pack columnBox
             columnbox.append(VPacker(pad=0,
diff --git a/lib/matplotlib/offsetbox.py b/lib/matplotlib/offsetbox.py
@@ -23,9 +23,9 @@
 from matplotlib.patches import bbox_artist as mbbox_artist
 DEBUG=False
 # for debuging use
-def bbox_artist(*kl, **kw):
+def bbox_artist(*args, **kwargs):
     if DEBUG:
-        mbbox_artist(*kl, **kw)
+        mbbox_artist(*args, **kwargs)
 
 
 # _get_packed_offsets() and _get_aligned_offsets() are coded assuming
@@ -122,9 +122,9 @@ class OffsetBox(martist.Artist):
     The OffsetBox is a simple container artist. The child artist are meant
     to be drawn at a relative position to its parent.  
     """
-    def __init__(self, *kl, **kw):
+    def __init__(self, *args, **kwargs):
 
-        super(OffsetBox, self).__init__(*kl, **kw)
+        super(OffsetBox, self).__init__(*args, **kwargs)
         
         self._children = []        
         self._offset = (0, 0)
@@ -441,10 +441,18 @@ class TextArea(OffsetBox):
 
 
     
-    def __init__(self, s, textprops=None, **kw):
-        """
-        *s* : a string to be displayer.
-        *trnaspose* : transformation matrrix 
+    def __init__(self, s,
+                 textprops=None,
+                 multilinebaseline=None,
+                 minimumdescent=True,
+                 ):
+        """
+        *s* : a string to be displayed.
+        *textprops* : property dictionary for the text
+        *multilinebaseline* : If True, baseline for multiline text is
+                              adjusted so that it is (approximatedly)
+                              center-aligned with singleline text.
+        *minimumdescent*  : If True, the box has a minimum descent of "p".
         """
         if textprops is None:
             textprops = {}
@@ -462,7 +470,46 @@ def __init__(self, s, textprops=None, **kw):
         self.offset_transform = mtransforms.Affine2D()
         self.offset_transform.clear()
         self.offset_transform.translate(0, 0)
-        self._text.set_transform(self.offset_transform)
+        self._baseline_transform = mtransforms.Affine2D()
+        self._text.set_transform(self.offset_transform+self._baseline_transform)
+
+        self._multilinebaseline = multilinebaseline
+        self._minimumdescent = minimumdescent
+        
+
+    def set_multilinebaseline(self, t):
+        """
+        Set multilinebaseline .
+
+        If True, baseline for multiline text is
+        adjusted so that it is (approximatedly) center-aligned with
+        singleline text.
+        """
+        self._multilinebaseline = t
+
+
+    def get_multilinebaseline(self):
+        """
+        get multilinebaseline .
+        """
+        return self._multilinebaseline
+
+
+    def set_minimumdescent(self, t):
+        """
+        Set minimumdescent .
+
+        If True, extent of the single line text is adjusted so that 
+        it has minimum descent of "p"
+        """
+        self._minimumdescent = t
+
+
+    def get_minimumdescent(self):
+        """
+        get minimumdescent.
+        """
+        return self._minimumdescent
 
 
     def set_transform(self, t):
@@ -507,17 +554,34 @@ def get_extent(self, renderer):
 
         bbox, info = self._text._get_layout(renderer)
         w, h = bbox.width, bbox.height
+
         line = info[0][0] # first line
 
         _, hh, dd = renderer.get_text_width_height_descent(
             line, self._text._fontproperties, ismath=ismath)
-        d = h-(hh-dd)  # the baseline of the first line
 
-        # for multiple lines, h or d may greater than h_ or d_.
-        h_d = max(h_ - d_, h-d)
-        d = max(d, d_)
-        h = h_d + d
 
+        self._baseline_transform.clear()
+        if len(info) > 1 and self._multilinebaseline: # multi line
+            d = h-(hh-dd)  # the baseline of the first line
+            d_new = 0.5 * h  - 0.5 * (h_ - d_)
+            
+            self._baseline_transform.translate(0, d - d_new)
+            d = d_new
+            
+        else: # single line
+
+            h_d = max(h_ - d_, h-dd)
+
+            if self.get_minimumdescent():
+                ## to have a minimum descent, #i.e., "l" and "p" have same
+                ## descents. 
+                d = max(dd, d_)
+            else:
+                d = dd
+
+            h = h_d + d
+            
         return w, h, 0., d
 
 
