chrome/browser/ui/panels/stacked_panel_drag_handler.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "chrome/browser/ui/panels/stacked_panel_drag_handler.h"
   6
   7 #include "base/logging.h"
   8 #include "chrome/browser/ui/panels/panel.h"
   9 #include "chrome/browser/ui/panels/panel_collection.h"
  10 #include "chrome/browser/ui/panels/stacked_panel_collection.h"
  11 #include "ui/gfx/geometry/point.h"
  12 #include "ui/gfx/geometry/rect.h"
  13
  14 // static
  15 void StackedPanelDragHandler::HandleDrag(Panel* panel,
  16                                          const gfx::Point& target_position,
  17                                          bool in_orginal_collection) {
  18   DCHECK_EQ(PanelCollection::STACKED, panel->collection()->type());
  19
  20   StackedPanelCollection* stack = panel->stack();
  21   DCHECK(stack);
  22
  23   // If the panel is in its original stack, only top panel is allowed to drag.
  24   if (in_orginal_collection && panel != stack->top_panel())
  25     return;
  26
  27   // Find out if all panels in the stack are being dragged.
  28   bool all_panels_under_drag = true;
  29   for (StackedPanelCollection::Panels::const_iterator iter =
  30            stack->panels().begin();
  31        iter != stack->panels().end(); ++iter) {
  32     if (!(*iter)->in_preview_mode()) {
  33       all_panels_under_drag = false;
  34       break;
  35     }
  36   }
  37
  38   gfx::Vector2d delta_origin = target_position - panel->GetBounds().origin();
  39
  40   // If not all panels in the stack are being dragged, it means that these
  41   // panels being dragged have just been added to this stack. Dragging these
  42   // panels should only cause the horizontal movement due to that y position
  43   // of these panels have already aligned.
  44   if (!all_panels_under_drag)
  45     delta_origin.set_y(0);
  46
  47   stack->MoveAllDraggingPanelsInstantly(delta_origin);
  48 }
  49
  50 // static
  51 void StackedPanelDragHandler::FinalizeDrag(Panel* panel) {
  52   DCHECK_EQ(PanelCollection::STACKED, panel->collection()->type());
  53
  54   StackedPanelCollection* stack = panel->stack();
  55   DCHECK(stack);
  56
  57   // It is only needed when dragging a panel/stack to stack to the top of
  58   // another panel/stack.
  59   if (stack->top_panel() != panel)
  60     return;
  61
  62   // Find the first non-dragging panel that is used to align all dragging panels
  63   // above it to have the same x position. This is because all dragging panels
  64   // are only aligned vertically when the stacking occurs.
  65   Panel* first_non_dragging_panel = NULL;
  66   for (StackedPanelCollection::Panels::const_iterator iter =
  67            stack->panels().begin();
  68        iter != stack->panels().end(); ++iter) {
  69     Panel* panel = *iter;
  70     if (!panel->in_preview_mode()) {
  71       first_non_dragging_panel = panel;
  72       break;
  73     }
  74   }
  75   if (!first_non_dragging_panel)
  76     return;
  77
  78   gfx::Vector2d delta_origin(
  79       first_non_dragging_panel->GetBounds().x() - panel->GetBounds().x(),
  80       0);
  81   stack->MoveAllDraggingPanelsInstantly(delta_origin);
  82 }