Changeset 82 for trunk

Timestamp:

03/21/08 15:05:51 (4 years ago)

Author:

lgs

Message:

Support for rendering the ticks with rotation. Also support for drawing labels in both axis. Based on patch sended by jae. View #6

Location:

trunk

Files:

• examples/barchart.py (modified) (2 diffs)
• examples/hbarchart.png (modified) (previous)
• examples/vbarchart.png (modified) (previous)
• src/chart.py (modified) (8 diffs)

trunk/examples/barchart.py

@@ -35 +35 @@
             'x': {
                 'ticks': [dict(v=i, label=l[0]) for i, l in enumerate(lines)],
+                'label': 'Files',
+                'rotate': 25,
             },
             'y': {
                 'tickCount': 4,
+                'rotate': 25,
+                'label': 'Lines'
             }
         },
@@ -50 +54 @@
         },
         'padding': {
-            'left': 55
+            'left': 55,
+            'bottom': 55,
         },
         'title': 'Sample Chart'

trunk/src/chart.py

@@ -17 +17 @@
 
 import copy
+import math
+
 import cairo
 
@@ -306 +308 @@
         raise NotImplementedError
 
+    def _renderYLabel(self, cx, tick):
+        """Aux method for _renderAxis"""
+
+        if callable(tick):
+            return
+
+        x = self.area.x
+        y = self.area.y + tick[0] * self.area.h
+
+        cx.new_path()
+        cx.move_to(x, y)
+        cx.line_to(x - self.options.axis.tickSize, y)
+        cx.close_path()
+        cx.stroke()
+
+        label =  unicode(tick[1])
+        extents = cx.text_extents(label)
+        labelWidth = extents[2]
+        labelHeight = extents[3]
+
+        if self.options.axis.y.rotate:
+            radians = math.radians(self.options.axis.y.rotate)
+            cx.move_to(x - self.options.axis.tickSize
+                       - (labelWidth * math.cos(radians))
+                       - 4,
+                       y + (labelWidth * math.sin(radians))
+                       + labelHeight / (2.0 / math.cos(radians)))
+            cx.rotate(-radians)
+            cx.show_text(label)
+            cx.rotate(radians) # this is probably faster than a save/restore
+        else:
+            cx.move_to(x - self.options.axis.tickSize - labelWidth - 4,
+                       y + labelHeight / 2.0)
+            cx.show_text(label)
+
+        return label
+
+    def _renderXLabel(self, cx, tick, fontAscent):
+        if callable(tick):
+            return
+
+        x = self.area.x + tick[0] * self.area.w
+        y = self.area.y + self.area.h
+
+        cx.new_path()
+        cx.move_to(x, y)
+        cx.line_to(x, y + self.options.axis.tickSize)
+        cx.close_path()
+        cx.stroke()
+
+        label = unicode(tick[1])
+        extents = cx.text_extents(label)
+        labelWidth = extents[2]
+        labelHeight = extents[3]
+
+        if self.options.axis.x.rotate:
+            radians = math.radians(self.options.axis.x.rotate)
+            cx.move_to(x - (labelHeight * math.cos(radians)),
+                       y + self.options.axis.tickSize
+                       + (labelHeight * math.cos(radians))
+                       + 4.0)
+            cx.rotate(radians)
+            cx.show_text(label)
+            cx.rotate(-radians)
+        else:
+            cx.move_to(x - labelWidth / 2.0,
+                       y + self.options.axis.tickSize
+                       + fontAscent + 4.0)
+            cx.show_text(label)
+        return label
+
+    def _getTickSize(self, cx, ticks, rotate):
+        tickExtents = [cx.text_extents(unicode(tick[1]))[2:4] for tick in ticks]
+        tickWidth = tickHeight = 0.0
+        if tickExtents:
+            tickHeight = tickHeight = self.options.axis.tickSize + 4.0
+            widths, heights = zip(*tickExtents)
+            maxWidth, maxHeight = max(widths), max(heights)
+            if rotate:
+                radians = math.radians(rotate)
+                sinRadians = math.sin(radians)
+                cosRadians = math.cos(radians)
+                maxHeight = maxWidth * sinRadians + maxHeight * cosRadians
+                maxWidth =  maxWidth * cosRadians + maxHeight * sinRadians
+            tickWidth += maxWidth
+            tickHeight += maxHeight
+        return tickWidth, tickHeight
+        
+    def _renderAxisLabel(self, cx, tickWidth, tickHeight, label, x, y, vertical=False):
+        cx.new_path()
+        cx.select_font_face(self.options.axis.labelFont,
+                            cairo.FONT_SLANT_NORMAL,
+                            cairo.FONT_WEIGHT_BOLD)
+        labelWidth = cx.text_extents(label)[2]
+        fontAscent = cx.font_extents()[0]
+        if vertical:
+            cx.move_to(x, y + labelWidth / 2)
+            radians = math.radians(90)
+            cx.rotate(-radians)
+        else:
+            cx.move_to(x - labelWidth / 2.0, y + fontAscent)
+            
+        cx.show_text(label)
+
     def _renderAxis(self, cx):
         """Renders axis"""
@@ -317 +423 @@
         if not self.options.axis.y.hide:
             if self.yticks:
-                def drawYLabel(tick):
-                    if callable(tick):
-                        return
-
-                    x = self.area.x
-                    y = self.area.y + tick[0] * self.area.h
-
-                    cx.new_path()
-                    cx.move_to(x, y)
-                    cx.line_to(x - self.options.axis.tickSize, y)
-                    cx.close_path()
-                    cx.stroke()
-
-                    label =  unicode(tick[1])
-                    extents = cx.text_extents(label)
-                    labelWidth = extents[2]
-                    labelHeight = extents[3]
-                    cx.move_to(x - self.options.axis.tickSize - labelWidth - 5,
-                               y + labelHeight / 2.0)
-                    cx.show_text(label)
-
-                    return label
                 for tick in self.yticks:
-                    drawYLabel(tick)
-
+                    self._renderYLabel(cx, tick)
+
+            if self.options.axis.y.label:
+                cx.save()
+                rotate = self.options.axis.y.rotate
+                tickWidth, tickHeight = self._getTickSize(cx, self.yticks, rotate)
+                label = unicode(self.options.axis.y.label)
+                x = self.area.x - tickWidth - 4.0
+                y = self.area.y + 0.5 * self.area.h
+                self._renderAxisLabel(cx, tickWidth, tickHeight, label, x, y, True)
+                cx.restore()
+
+            # draws the vertical line representing the Y axis
             cx.new_path()
             cx.move_to(self.area.x, self.area.y)
@@ -349 +444 @@
 
         if not self.options.axis.x.hide:
+            fontAscent = cx.font_extents()[0]
             if self.xticks:
-                def drawXLabel(tick):
-                    if callable(tick):
-                        return
-
-                    x = self.area.x + tick[0] * self.area.w
-                    y = self.area.y + self.area.h
-
-                    cx.new_path()
-                    cx.move_to(x, y)
-                    cx.line_to(x, y + self.options.axis.tickSize)
-                    cx.close_path()
-                    cx.stroke()
-
-                    label = unicode(tick[1])
-                    extents = cx.text_extents(label)
-                    labelWidth = extents[2]
-                    labelHeight = extents[3]
-                    cx.move_to(x - labelWidth / 2.0,
-                               y + self.options.axis.tickSize + 10)
-                    cx.show_text(label)
-                    return label
                 for tick in self.xticks:
-                    drawXLabel(tick)
-
+                    self._renderXLabel(cx, tick, fontAscent)
+
+            if self.options.axis.x.label:
+                cx.save()
+                rotate = self.options.axis.x.rotate
+                tickWidth, tickHeight = self._getTickSize(cx, self.xticks, rotate)
+                label = unicode(self.options.axis.x.label)
+                x = self.area.x + self.area.w / 2.0
+                y = self.area.y + self.area.h + tickHeight + 4.0
+                self._renderAxisLabel(cx, tickWidth, tickHeight, label, x, y, False)
+                cx.restore()
+
+            # draws the horizontal line representing the X axis
             cx.new_path()
             cx.move_to(self.area.x, self.area.y + self.area.h)
@@ -384 +470 @@
     def _renderTitle(self, cx):
         if self.options.title:
-            # get previous font information
-            oldFace = cx.get_font_face()
-            oldMatrix = cx.get_font_matrix()
-            
+            cx.save()           
             cx.select_font_face(self.options.titleFont,
                                 cairo.FONT_SLANT_NORMAL,
@@ -403 +486 @@
             cx.show_text(title)
             
-            # restore font state
-            cx.set_font_face(oldFace)
-            cx.set_font_matrix(oldMatrix)
+            cx.restore()
 
     def _renderLegend(self, cx):
@@ -494 +575 @@
             tickPrecision=1,
             range=None,
+            rotate=None,
+            label=None,
         ),
         y=Option(
@@ -501 +584 @@
             tickPrecision=1,
             range=None,
+            rotate=None,
+            label=None,
         ),
     ),