pitivi r1157 - in branches/SOC_2008_BLEWIS: . pitivi/ui

[blewis svn gnome org]

Author: blewis
Date: Wed Jul  9 10:24:07 2008
New Revision: 1157
URL: http://svn.gnome.org/viewvc/pitivi?rev=1157&view=rev

Log:
* pitivi/ui/util.py:
check in selection managment code taken from gst-editor.py


Modified:
   branches/SOC_2008_BLEWIS/ChangeLog
   branches/SOC_2008_BLEWIS/pitivi/ui/util.py

Modified: branches/SOC_2008_BLEWIS/pitivi/ui/util.py
==============================================================================
--- branches/SOC_2008_BLEWIS/pitivi/ui/util.py	(original)
+++ branches/SOC_2008_BLEWIS/pitivi/ui/util.py	Wed Jul  9 10:24:07 2008
@@ -209,6 +209,119 @@
 def unmake_resizable(item):
     pass
 
+def normalize_rect(mouse_down, cur_pos):
+    """Given two points, representing the upper left and bottom right 
+    corners of a rectangle (the order is irrelevant), return the tuple
+    ((x,y), (width, height))"""
+    w, h = point_difference(cur_pos, mouse_down)
+    x, y = mouse_down
+
+    if w < 0:
+        w = abs(w)
+        x -= w
+    if h < 0:
+        h = abs(h)
+        y -= h
+
+    return (x, y), (w, h)
+
+def object_select_cb(item, target, event, canvas, changed_cb):
+    prev = canvas.get_data("selected_objects")
+    if item in prev:
+        return
+    if (event.state & gtk.gdk.SHIFT_MASK):
+        prev.add(item)
+        changed_cb(prev, set())
+    else:
+        selected = set()
+        selected.add(item)
+        canvas.set_data("selected_objects", selected)
+        changed_cb(selected, prev)
+    return False
+
+def make_selectable(canvas, object):
+    """Make the object selectable with respect to canvas. This means
+    that the item will be included in the current selection, and that
+    clicking the object will select it. Must be called before 
+    make_dragable, as it will block the action of this handler"""
+    object.set_data("selectable", True)
+    object.connect("button_press_event", object_select_cb, canvas,
+        canvas.get_data("selection_callback"))
+
+def delete_from_selection(canvas, item):
+    selected = canvas.get_data("selected_objects")
+    set_selection(canvas, selected - set([item]))
+
+def set_selection(canvas, new):
+    prev = canvas.get_data("selected_objects")
+    deselected = prev - new
+    canvas.set_data("selected_objects", new)
+    canvas.get_data("selection_callback")(new, deselected)
+
+def manage_selection(canvas, marquee, overlap, changed_cb=None):
+    """Keep track of the current selection in canvas, including
+    * providing a rectangular selection marquee
+    * tracking specific canvas objects
+    Note: objects must be made selectable by calling make_selectable()
+    on the object before they will be reported by any selection changes
+    - overlap: True if you want items that merely intersect the 
+        data field to be considered selected.
+    - marquee: a goocanvas.Rectangle() to be used as the selection 
+        marquee (really, any canvas item with x, y, width, height 
+        properties). This object should not already be added to the
+        canvas.
+    - changed_cb: a callback with signature (selected, deselected)
+      """
+
+    def objects_under_marquee(event):
+        pos, size = normalize_rect(mouse_down[0], event_coords(
+            canvas, event))
+        bounds = goocanvas.Bounds(*(pos + point_sum(pos, size)))
+        selected = canvas.get_items_in_area(bounds, True, overlap, 
+            containers)
+        if selected:
+            return set((found for found in selected if 
+                found.get_data("selectable")))
+        return set()
+
+    def selection_start(item, target, event):
+        root.add_child(marquee)
+        cursor = event_coords(canvas, event)
+        set_pos(marquee, cursor)
+        selecting[0] = True
+        mouse_down[0] = cursor
+        set_pos(marquee, cursor) 
+        set_size(marquee, (0, 0))
+        return True
+
+    def selection_end(item, target, event):
+        selecting[0] = False
+        marquee.remove()
+        prev = canvas.get_data("selected_objects")
+        selected = objects_under_marquee(event)
+        canvas.set_data("selected_objects", selected)
+        if changed_cb:
+            changed_cb(selected, prev.difference(selected))
+        return True
+
+    def selection_drag(item, target, event):
+        if selecting[0]:
+            pos_, size_ = normalize_rect(mouse_down[0], 
+                event_coords(canvas, event))
+            set_size(marquee, size_)
+            set_pos(marquee, pos_)
+            return True
+        return False
+
+    canvas.set_data("selected_objects", set())
+    canvas.set_data("selection_callback", changed_cb)
+    containers = True
+    selecting = [False]
+    mouse_down = [None]
+    root = canvas.get_root_item()
+    root.connect("button_press_event", selection_start)
+    root.connect("button_release_event", selection_end)
+    root.connect("motion_notify_event", selection_drag)
 
 class Text(goocanvas.Text):
     '''adds the "missing" height property to goocanvas.Text'''