Add a very basic Image component.

enable/primitives/image.py

@@ -0,0 +1,68 @@
+""" Defines the Label class.
+"""
+
+from __future__ import absolute_import
+
+# Enthought library imports
+from traits.api import Array, Bool, Enum, Instance, Property, cached_property
+
+# Local imports
+from enable.component import Component
+from kiva.image import GraphicsContext
+
+
+class Image(Component):
+    """ Component that displays a static image
+
+    This is extremely simple right now.  By default it will draw the array into
+    the entire region occupied by the component, stretching or shrinking as
+    needed.  It is up to the user to set the bounds, although the from_file
+    will give something sensible, and we assume that a constraints-based layout
+    should have a layour_size_hint of the image size.
+
+    """
+
+    #: the image data as an array
+    data = Array(dtype='uint8')
+
+    #: the format of the image data (eg. RGB vs. RGBA)
+    format = Property(Enum('rgb24', 'rgba32'))
+
+    #: the size-hint for constraints-based layout
+    layout_size_hint = Property(data)
+
+    #: the image as an Image GC
+    _image = Property(Instance(GraphicsContext), depends_on='data')
+
+    @classmethod
+    def from_file(cls, filename):
+        from scipy.misc import imread
+        data = imread(filename)
+        return cls(data=data, bounds=data.shape[:2])
+
+    def _draw_mainlayer(self, gc, view_bounds=None, mode="normal"):
+        """ Draws the image. """
+        with gc:
+            gc.draw_image(self._image, (self.x, self.y, self.width, self.height))
+
+    @cached_property
+    def _get_format(self):
+        if self.data.shape[-1] == 3:
+            return 'rgb24'
+        elif self.data.shape[-1] == 4:
+            return 'rgba32'
+        else:
+            raise ValueError('Data array not correct shape')
+
+    @cached_property
+    def _get_layout_size_hint(self):
+        return self.data.shape[:2]
+
+    @cached_property
+    def _get__image(self):
+        if not self.data.flags['C_CONTIGUOUS']:
+            data = self.data.copy()
+        else:
+            data = self.data
+        image_gc = GraphicsContext(data, pix_format=self.format)
+        return image_gc

examples/enable/image_draw.py

@@ -0,0 +1,35 @@
+"""
+This demonstrates the most basic drawing capabilities using Enable.  A new
+component is created and added to a container.
+"""
+import os
+from enable.example_support import DemoFrame, demo_main
+from enable.api import ConstraintsContainer, Window
+from enable.primitives.image import Image
+
+THIS_DIR = os.path.split(__file__)[0]
+
+class MyFrame(DemoFrame):
+
+    def _create_window(self):
+        path = os.path.join(THIS_DIR, 'deepfield.jpg')
+        image = Image.from_file(path)
+        image.resist_width = 'weak'
+        image.resist_height = 'weak'
+        container = ConstraintsContainer(bounds=[500, 500])
+        container.add(image)
+        ratio = float(image.data.shape[1])/image.data.shape[0]
+        container.layout_constraints = [
+            image.left == container.contents_left,
+            image.right == container.contents_right,
+            image.top == container.contents_top,
+            image.bottom == container.contents_bottom,
+            image.layout_width == ratio*image.layout_height,
+        ]
+        return Window(self, -1, component=container)
+
+
+if __name__ == "__main__":
+    # Save demo so that it doesn't get garbage collected when run within
+    # existing event loop (i.e. from ipython).
+    demo = demo_main(MyFrame)