Added a Python version of the Bar Chart example.

1 files changed, 135 insertions, 0 deletions

diff --git a/barchart/barchart.py b/barchart/barchart.py
new file mode 100644
index 0000000..67a2e86
--- /dev/null
+++ b/barchart/barchart.py
@@ -0,0 +1,135 @@
+#############################################################################
+##
+## Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+## Contact: Qt Software Information (qt-info@nokia.com)
+##
+## This file is part of the Graphics Dojo project on Qt Labs.
+##
+## This file may be used under the terms of the GNU General Public
+## License version 2.0 or 3.0 as published by the Free Software Foundation
+## and appearing in the file LICENSE.GPL included in the packaging of
+## this file.  Please review the following information to ensure GNU
+## General Public Licensing requirements will be met:
+## http:#www.fsf.org/licensing/licenses/info/GPLv2.html and
+## http:#www.gnu.org/copyleft/gpl.html.
+##
+## If you are unsure which license is appropriate for your use, please
+## contact the sales department at qt-sales@nokia.com.
+##
+## This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
+## WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
+##
+#############################################################################
+
+import sys
+from PyQt4.QtCore import QPointF, QSize, Qt
+from PyQt4.QtGui import *
+
+class BarChart(QWidget):
+
+    def __init__(self, parent = None):
+    
+        QWidget.__init__(self, parent)
+        self.suffix = ""
+    
+    def showEvent(self, event):
+    
+        # find the maximum value and widest (pixel-wise) label and suffix
+        fm = QFontMetrics(self.font())
+        
+        self.margin = 20
+        self.titleHeight = fm.height()
+        self.barHeight = 1.5 * fm.height()
+        self.barSpacing = 0.6 * fm.height()
+        
+        self.maxValue = self.suffixWidth = self.labelWidth = 0
+        count = 0
+        for key, value in self.data.items():
+            self.labelWidth = max(self.labelWidth, fm.width(key))
+            self.maxValue = max(self.maxValue, value)
+            self.suffixWidth = max(self.suffixWidth, fm.width(str(value) + " " + self.suffix))
+            count += 1
+    
+        self.startHue = 15
+        self.hueDelta = 360 / count
+    
+        self.resize(QSize(640, self.titleHeight + 2 * self.margin + (self.barHeight + self.barSpacing) * count))
+    
+    def paintEvent(self, event):
+    
+        p = QPainter()
+        p.begin(self)
+    
+        # background and title
+        p.fillRect(self.rect(), QBrush(QColor(255, 255, 255)))
+        p.drawText(0, 0, self.width(), self.margin + self.titleHeight, Qt.AlignCenter, self.windowTitle())
+    
+        ofs = self.labelWidth + self.margin
+        ww = self.width() - self.suffixWidth - ofs - 2 * self.margin
+        hue = self.startHue
+        y = 0
+    
+        p.translate(self.margin, self.titleHeight + 1.5 * self.margin)
+    
+        for key, value in self.data.items():
+    
+            # label on the left side
+            p.setPen(QColor(Qt.black))
+            p.drawText(0, y, self.labelWidth, self.barHeight, Qt.AlignVCenter + Qt.AlignRight, key)
+    
+            # the colored bar
+            gradient = QLinearGradient(QPointF(ofs, y), QPointF(ofs, y + self.barHeight))
+            gradient.setColorAt(0, QColor.fromHsv(hue, 255, 240))
+            gradient.setColorAt(1, QColor.fromHsv(hue, 255, 92))
+            p.setBrush(QBrush(gradient))
+            p.setPen(QColor(96, 96, 96))
+            bw = value * ww / self.maxValue
+            p.drawRect(ofs, y, bw, self.barHeight)
+    
+            # extra text at the end of the bar
+            text = str(value) + " " + self.suffix
+            p.setPen(QColor(Qt.black))
+            p.drawText(ofs + bw + self.margin/2, y, self.suffixWidth, self.barHeight, Qt.AlignVCenter + Qt.AlignLeft, text)
+    
+            # for the next bar
+            y += (self.barHeight + self.barSpacing)
+            hue += self.hueDelta
+            if hue >= 360:
+                hue -= 360
+        
+        p.end()
+    
+    def wheelEvent(self, event):
+        self.startHue += event.delta() / 8 / 5
+        if self.startHue >= 360:
+            self.startHue -= 360
+        if self.startHue < 0:
+            self.startHue += 360
+        self.update()
+        event.ignore()
+    
+    def mousePressEvent(self, event):
+        fname = QFileDialog.getSaveFileName(self, "Save", ".", "*.png", 0, 0)
+        if fname.length > 0:
+            img = QImage(self.size(), QImage.Format_ARGB32_Premultiplied)
+            self.render(img)
+            img.save(QFile(fname))
+
+
+if __name__ == "__main__":
+
+    app = QApplication(sys.argv)
+    chart = BarChart()
+    
+    chart.setWindowTitle("SquirrelFish Performance")
+    
+    chart.suffix = "runs"
+    
+    chart.data = {"WebKit 3.0" :  5.4, 
+                  "WebKit 3.1" : 18.8,
+                "SquirrelFish" : 29.9,
+        "SquirrelFish Extreme" : 63.6}
+    
+    chart.show()
+    sys.exit(app.exec_())
+