exportTo: improved arguments consistency (resolution, size, size_mm)

Author: Pierre Raybaut

examples/ReallySimpleDemo.py

@@ -71,5 +71,5 @@ def make():
 if __name__ == '__main__':
     app = Qt.QApplication(sys.argv)
     demo = make()
-    demo.exportTo("demo.pdf")
+    demo.exportTo("demo.png", size=(1600, 900), resolution=200)
     sys.exit(app.exec_())

qwt/qwt_plot.py

@@ -833,10 +833,13 @@ def print_(self, printer):
         renderer = QwtPlotRenderer(self)
         renderer.renderTo(self, printer)
 
-    def exportTo(self, filename, size=(300, 200), resolution=85, format_=None):
+    def exportTo(self, filename, size=(800, 600), size_mm=None,
+                 resolution=72., format_=None):
+        if size_mm is None:
+            size_mm = tuple(25.4*np.array(size)/resolution)
         from qwt.qwt_plot_renderer import QwtPlotRenderer
         renderer = QwtPlotRenderer(self)
-        renderer.renderDocument(self, filename, size, resolution, format_)
+        renderer.renderDocument(self, filename, size_mm, resolution, format_)
 
 
 class QwtPlotItem_PrivateData(object):

qwt/qwt_text.py

@@ -10,8 +10,6 @@
 import math
 
 
-
-
 class QwtText_PrivateData(object):
     def __init__(self):
         self.renderFlags = Qt.AlignCenter