Merge pull request #246 from enthought/demo/kiva-explorer

Kiva explorer demo

examples/kiva_explorer.py

@@ -0,0 +1,110 @@
+"""
+Kiva Explorer
+=============
+
+Interactive editor for exploring Kiva drawing commands.
+
+"""
+
+from traits.api import Any, Code, Instance, Str
+from traitsui.api import HSplit, ModelView, UItem, VGroup, View
+from enable.api import Component, ComponentEditor
+
+
+default_script = """# Write your code here.
+# The graphics context is available as gc.
+
+from math import pi
+from kiva import constants
+from kiva.fonttools import Font
+
+with gc:
+    gc.set_fill_color((1.0, 1.0, 0.0, 1.0))
+    gc.arc(200, 200, 100, 0, 2*pi)
+    gc.fill_path()
+
+    with gc:
+        gc.set_font(Font('Times New Roman', size=24))
+        gc.translate_ctm(200, 200)
+        for i in range(0, 12):
+            gc.set_fill_color((i/12.0, 0.0, 1.0-(i/12.0), 0.75))
+            gc.rotate_ctm(2*pi/12.0)
+            gc.show_text_at_point("Hello World", 20, 0)
+
+    gc.set_stroke_color((0.0, 0.0, 1.0, 1.0))
+    gc.set_line_width(7)
+    gc.set_line_join(constants.JOIN_ROUND)
+    gc.set_line_cap(constants.CAP_ROUND)
+    gc.rect(100, 400, 50, 50)
+    gc.stroke_path()
+
+"""
+
+
+class ScriptedComponent(Component):
+    """ An Enable component that draws its mainlayer from a script """
+
+    #: kiva drawing code for mainlayer
+    draw_script = Code(default_script)
+
+    #: any errors which occur
+    error = Str
+
+    #: compiled code
+    _draw_code = Any
+
+    def _draw_mainlayer(self, gc, view_bounds=None, mode="default"):
+        """ Try running the compiled code with the graphics context as `gc` """
+        with gc:
+            try:
+                self.error = ''
+                exec self._draw_code in {}, {'gc': gc}
+            except Exception as exc:
+                self.error = str(exc)
+
+    def _compile_script(self):
+        """ Try compiling the script to bytecode """
+        try:
+            self.error = ''
+            return compile(self.draw_script, "<script>", "exec")
+        except SyntaxError as exc:
+            self.error = str(exc)
+            return None
+
+    def _draw_script_changed(self):
+        code = self._compile_script()
+        if code is not None:
+            self._draw_code = code
+        self.request_redraw()
+
+    def __draw_code_default(self):
+        code = self._compile_script()
+        if code is None:
+            code = compile("", "<script>", "exec")
+        return code
+
+
+class ScriptedComponentView(ModelView):
+    """ ModelView of a ScriptedComponent displaying the script and image """
+
+    #: the component we are editing
+    model = Instance(ScriptedComponent, ())
+
+    view = View(
+        HSplit(
+            VGroup(
+                UItem('model.draw_script'),
+                UItem(
+                    'model.error',
+                    visible_when="model.error != ''",
+                    style='readonly',
+                    height=100)
+            ),
+            UItem('model', editor=ComponentEditor()),
+        ),
+        resizable=True
+    )
+
+if __name__ == '__main__':
+    view = ScriptedComponentView()
+    view.configure_traits()