[pitivi] ui.curve: check in curve canvas item module

[Edward Hervey <edwardrv src gnome org>]

commit 1eaf21e5c02c557ba58be6d402c0699bf0fba968
Author: Brandon Lewis <brandon_lewis berkeley edu>
Date:   Thu May 28 13:23:53 2009 -0700

    ui.curve: check in curve canvas item module

 pitivi/ui/curve.py |  110 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 110 insertions(+), 0 deletions(-)
---
diff --git a/pitivi/ui/curve.py b/pitivi/ui/curve.py
new file mode 100644
index 0000000..303ca09
--- /dev/null
+++ b/pitivi/ui/curve.py
@@ -0,0 +1,110 @@
+# PiTiVi , Non-linear video editor
+#
+#       pitivi/ui/curve.py
+#
+# Copyright (c) 2006, Edward Hervey <bilboed bilboed com>
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2.1 of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this program; if not, write to the
+# Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+# Boston, MA 02111-1307, USA.
+
+"""
+Custom canvas item for track object keyframe curves."""
+
+import goocanvas
+import gobject
+
+from pitivi.receiver import receiver, handler
+from pitivi.ui.zoominterface import Zoomable
+import pitivi.ui.previewer as previewer
+
+def between(a, b, c):
+    return (a <= b) and (b <= c)
+
+def intersect(b1, b2):
+    return goocanvas.Bounds(max(b1.x1, b2.x1), max(b1.y1, b2.y1),
+        min(b1.x2, b2.x2), min(b1.y2, b2.y2))
+
+class Curve(goocanvas.ItemSimple, goocanvas.Item, Zoomable):
+
+    __gtype_name__ = 'Curve'
+
+    def __init__(self, element, interpolator, height=50, **kwargs):
+        super(Curve, self).__init__(**kwargs)
+        Zoomable.__init__(self)
+        self.height = float(height)
+        self.element = element
+        self.props.pointer_events = False
+        self.interpolator = interpolator
+
+## properties
+
+    def _get_height(self):
+        return self._height
+    def _set_height (self, value):
+        self._height = value
+        self.changed(True)
+    height = gobject.property(_get_height, _set_height, type=float)
+
+## element callbacks
+
+    def _set_element(self):
+        self.previewer = previewer.get_preview_for_object(self.element)
+    element = receiver(setter=_set_element)
+
+    @handler(element, "in-point-changed")
+    @handler(element, "media-duration-changed")
+    def _media_props_changed(self, obj, unused_start_duration):
+        self.changed(True)
+
+## interpolator callbacks
+
+    interpolator = receiver()
+
+## Zoomable interface overries
+
+    def zoomChanged(self):
+        self.changed(True)
+
+## goocanvas item methods
+
+    def do_simple_update(self, cr):
+        cr.identity_matrix()
+        if self.element.factory:
+            self.bounds = goocanvas.Bounds(0, 0,
+            Zoomable.nsToPixel(self.element.duration), self.height)
+
+    def _getKeyframeXY(self, kf):
+        x = self.nsToPixel(kf.time + self.element.start)
+        y = kf.value * self._height
+        return x, y
+
+    def do_simple_paint(self, cr, bounds):
+        bounds = intersect(self.bounds, bounds)
+        cr.identity_matrix()
+        height = bounds.y2 - bounds.y1
+        width = bounds.x2 - bounds.x1
+        if self.element.factory:
+            cr.rectangle(bounds.x1, bounds.x2, width, height)
+            cr.clip()
+            cr.move_to(*self._getKeyframeXY(self.interpolator.start))
+            if self.interpolator:
+                for kf in self.interpolator.getPoints():
+                    cr.line_to(*self._getKeyframeXY(kf))
+            cr.line_to(self.interpolator.end)
+            cr.stroke()
+
+    def do_simple_is_item_at(self, x, y, cr, pointer_event):
+        return (between(0, x, self.nsToPixel(self.element.duration)) and
+            between(0, y, self.height))