chrome/browser/ui/views/panels/x11_panel_resizer.h

   1 // Copyright 2014 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 #ifndef CHROME_BROWSER_UI_VIEWS_PANELS_X11_PANEL_RESIZER_H_
   6 #define CHROME_BROWSER_UI_VIEWS_PANELS_X11_PANEL_RESIZER_H_
   7
   8 #include "ui/events/event_handler.h"
   9 #include "ui/gfx/geometry/point.h"
  10
  11 namespace aura {
  12 class Window;
  13 }
  14
  15 class Panel;
  16
  17 // EventHandler which implements special handling for resizing panels. Panels
  18 // should use X11PanelResizer instead of X11WindowEventFilter.
  19 // When resizing a panel:
  20 // - The panel bounds should update in sync with the user's mouse movement
  21 //   during the resize operation.
  22 // - The layout of all of the panels should be updated once the resize operation
  23 //   completes.
  24 // X11PanelResizer does not hand off resizing to the window manager because it
  25 // is not possible to determine when the window manager has finished resizing.
  26 class X11PanelResizer : public ui::EventHandler {
  27  public:
  28   X11PanelResizer(Panel* panel, aura::Window* window);
  29   ~X11PanelResizer() override;
  30
  31  private:
  32   enum ResizeState {
  33     NOT_RESIZING,
  34
  35     // The user has clicked on one of the panel's edges.
  36     RESIZE_CAN_START,
  37
  38     // The user has dragged one of the panel's edges far enough for resizing to
  39     // begin.
  40     RESIZE_IN_PROGRESS
  41   };
  42
  43   // Called as a result of ET_MOUSE_PRESSED.
  44   void OnMousePressed(ui::MouseEvent* event);
  45
  46   // Called as a result of ET_MOUSE_DRAGGED.
  47   void OnMouseDragged(ui::MouseEvent* event);
  48
  49   // Stops the resize operation if one is in progress. Consumes |event| if it
  50   // is not NULL and the resize operation was stopped.
  51   void StopResizing(ui::MouseEvent* event, bool canceled);
  52
  53   // ui::EventHandler:
  54   void OnMouseEvent(ui::MouseEvent* event) override;
  55
  56   // The panel being resized.
  57   Panel* panel_;
  58
  59   // |panel|'s window.
  60   aura::Window* window_;
  61
  62   ResizeState resize_state_;
  63
  64   // The edge that the user is resizing.
  65   int resize_component_;
  66
  67   // The location of the mouse click on the window border.
  68   gfx::Point initial_press_location_in_screen_;
  69
  70   DISALLOW_COPY_AND_ASSIGN(X11PanelResizer);
  71 };
  72
  73 #endif  // CHROME_BROWSER_UI_VIEWS_PANELS_X11_PANEL_RESIZER_H_