chrome/browser/ui/panels/docked_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/docked_panel_drag_handler.h"
   6
   7 #include "chrome/browser/ui/panels/docked_panel_collection.h"
   8 #include "chrome/browser/ui/panels/panel.h"
   9 #include "chrome/browser/ui/panels/panel_manager.h"
  10 #include "ui/gfx/point.h"
  11 #include "ui/gfx/rect.h"
  12
  13 // static
  14 void DockedPanelDragHandler::HandleDrag(Panel* panel,
  15                                         const gfx::Point& target_position) {
  16   DCHECK_EQ(PanelCollection::DOCKED, panel->collection()->type());
  17
  18   DockedPanelCollection* collection =
  19       static_cast<DockedPanelCollection*>(panel->collection());
  20
  21   // Moves this panel to the dragging position.
  22   // Note that we still allow the panel to be moved vertically until it gets
  23   // aligned to the bottom area.
  24   gfx::Rect new_bounds(panel->GetBounds());
  25   new_bounds.set_x(target_position.x());
  26   int delta_x = new_bounds.x() - panel->GetBounds().x();
  27   int bottom = collection->GetBottomPositionForExpansionState(
  28       panel->expansion_state());
  29   if (new_bounds.bottom() != bottom) {
  30     new_bounds.set_y(target_position.y());
  31     if (new_bounds.bottom() > bottom)
  32       new_bounds.set_y(bottom - new_bounds.height());
  33   }
  34   panel->SetPanelBoundsInstantly(new_bounds);
  35
  36   if (delta_x) {
  37     // Checks and processes other affected panels.
  38     if (delta_x > 0)
  39       DragRight(panel);
  40     else
  41       DragLeft(panel);
  42
  43     // Layout refresh will automatically recompute the bounds of all affected
  44     // panels due to their position changes.
  45     collection->RefreshLayout();
  46   }
  47 }
  48
  49 // static
  50 void DockedPanelDragHandler::DragLeft(Panel* panel) {
  51   DockedPanelCollection* collection =
  52       static_cast<DockedPanelCollection*>(panel->collection());
  53
  54   // This is the left corner of the dragging panel. We use it to check against
  55   // all the panels on its left.
  56   int dragging_panel_left_boundary = panel->GetBounds().x();
  57
  58   // Checks the panels to the left of the dragging panel.
  59   DockedPanelCollection::Panels::iterator dragging_panel_iterator =
  60       find(collection->panels_.begin(), collection->panels_.end(), panel);
  61   DockedPanelCollection::Panels::iterator current_panel_iterator =
  62       dragging_panel_iterator;
  63   ++current_panel_iterator;
  64   for (; current_panel_iterator != collection->panels_.end();
  65        ++current_panel_iterator) {
  66     Panel* current_panel = *current_panel_iterator;
  67
  68     // Can we swap dragging panel with its left panel? The criterion is that
  69     // the left corner of dragging panel should pass the middle position of
  70     // its left panel.
  71     if (dragging_panel_left_boundary > current_panel->GetBounds().x() +
  72             current_panel->GetBounds().width() / 2)
  73       break;
  74
  75     // Swaps the contents and makes |dragging_panel_iterator| refers to the new
  76     // position.
  77     *dragging_panel_iterator = current_panel;
  78     *current_panel_iterator = panel;
  79     dragging_panel_iterator = current_panel_iterator;
  80   }
  81 }
  82
  83 // static
  84 void DockedPanelDragHandler::DragRight(Panel* panel) {
  85   DockedPanelCollection* collection =
  86       static_cast<DockedPanelCollection*>(panel->collection());
  87
  88   // This is the right corner of the dragging panel. We use it to check against
  89   // all the panels on its right.
  90   int dragging_panel_right_boundary = panel->GetBounds().x() +
  91       panel->GetBounds().width() - 1;
  92
  93   // Checks the panels to the right of the dragging panel.
  94   DockedPanelCollection::Panels::iterator dragging_panel_iterator =
  95       find(collection->panels_.begin(), collection->panels_.end(), panel);
  96   DockedPanelCollection::Panels::iterator current_panel_iterator =
  97       dragging_panel_iterator;
  98   while (current_panel_iterator != collection->panels_.begin()) {
  99     current_panel_iterator--;
 100     Panel* current_panel = *current_panel_iterator;
 101
 102     // Can we swap dragging panel with its right panel? The criterion is that
 103     // the left corner of dragging panel should pass the middle position of
 104     // its right panel.
 105     if (dragging_panel_right_boundary < current_panel->GetBounds().x() +
 106             current_panel->GetBounds().width() / 2)
 107       break;
 108
 109     // Swaps the contents and makes |dragging_panel_iterator| refers to the new
 110     // position.
 111     *dragging_panel_iterator = current_panel;
 112     *current_panel_iterator = panel;
 113     dragging_panel_iterator = current_panel_iterator;
 114   }
 115 }