ui/views/browser_actions_container.h

// Copyright (c) 2011 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CHROME_BROWSER_UI_VIEWS_BROWSER_ACTIONS_CONTAINER_H_
#define CHROME_BROWSER_UI_VIEWS_BROWSER_ACTIONS_CONTAINER_H_
#pragma once

#include <set>
#include <string>
#include <vector>

#include "base/task.h"
#include "chrome/browser/extensions/extension_context_menu_model.h"
#include "chrome/browser/extensions/extension_toolbar_model.h"
#include "chrome/browser/extensions/image_loading_tracker.h"
#include "chrome/browser/ui/views/browser_bubble.h"
#include "chrome/browser/ui/views/extensions/browser_action_overflow_menu_controller.h"
#include "chrome/browser/ui/views/extensions/extension_popup.h"
#include "chrome/common/notification_observer.h"
#include "chrome/common/notification_registrar.h"
#include "ui/base/animation/animation_delegate.h"
#include "ui/base/animation/tween.h"
#include "views/controls/button/menu_button.h"
#include "views/controls/menu/view_menu_delegate.h"
#include "views/controls/resize_area.h"
#include "views/view.h"

class Browser;
class BrowserActionsContainer;
class BrowserActionOverflowMenuController;
class BrowserActionsContainer;
class Extension;
class ExtensionAction;
class ExtensionPopup;
class PrefService;
class Profile;

namespace gfx {
class CanvasSkia;
}

namespace ui {
class SlideAnimation;
}

namespace views {
class Menu2;
}

////////////////////////////////////////////////////////////////////////////////
// BrowserActionButton

// The BrowserActionButton is a specialization of the MenuButton class.
// It acts on a ExtensionAction, in this case a BrowserAction and handles
// loading the image for the button asynchronously on the file thread.
class BrowserActionButton : public views::MenuButton,
                            public views::ButtonListener,
                            public ImageLoadingTracker::Observer,
                            public NotificationObserver {
 public:
  BrowserActionButton(const Extension* extension,
                      BrowserActionsContainer* panel);

  // Call this instead of delete.
  void Destroy();

  ExtensionAction* browser_action() const { return browser_action_; }
  const Extension* extension() { return extension_; }

  // Called to update the display to match the browser action's state.
  void UpdateState();

  // Returns the default icon, if any.
  const SkBitmap& default_icon() const { return default_icon_; }

  // Overridden from views::View:
  virtual void ViewHierarchyChanged(bool is_add, View* parent, View* child);

  // Overridden from views::ButtonListener:
  virtual void ButtonPressed(views::Button* sender, const views::Event& event);

  // Overridden from ImageLoadingTracker.
  virtual void OnImageLoaded(
      SkBitmap* image, ExtensionResource resource, int index);

  // Overridden from NotificationObserver:
  virtual void Observe(NotificationType type,
                       const NotificationSource& source,
                       const NotificationDetails& details);

  // MenuButton behavior overrides.  These methods all default to TextButton
  // behavior unless this button is a popup.  In that case, it uses MenuButton
  // behavior.  MenuButton has the notion of a child popup being shown where the
  // button will stay in the pushed state until the "menu" (a popup in this
  // case) is dismissed.
  virtual bool Activate();
  virtual bool OnMousePressed(const views::MouseEvent& e);
  virtual void OnMouseReleased(const views::MouseEvent& e, bool canceled);
  virtual bool OnKeyReleased(const views::KeyEvent& e);
  virtual void OnMouseExited(const views::MouseEvent& event);
  virtual void ShowContextMenu(const gfx::Point& p, bool is_mouse_gesture);

  // Does this button's action have a popup?
  virtual bool IsPopup();
  virtual GURL GetPopupUrl();

  // Notifications when to set button state to pushed/not pushed (for when the
  // popup/context menu is hidden or shown by the container).
  void SetButtonPushed();
  void SetButtonNotPushed();

 private:
  virtual ~BrowserActionButton();

  // The browser action this view represents. The ExtensionAction is not owned
  // by this class.
  ExtensionAction* browser_action_;

  // The extension associated with the browser action we're displaying.
  const Extension* extension_;

  // The object that is waiting for the image loading to complete
  // asynchronously.
  ImageLoadingTracker tracker_;

  // Whether we are currently showing/just finished showing a context menu.
  bool showing_context_menu_;

  // The default icon for our browser action. This might be non-empty if the
  // browser action had a value for default_icon in the manifest.
  SkBitmap default_icon_;

  // The browser action shelf.
  BrowserActionsContainer* panel_;

  scoped_refptr<ExtensionContextMenuModel> context_menu_contents_;
  scoped_ptr<views::Menu2> context_menu_menu_;

  NotificationRegistrar registrar_;

  friend class DeleteTask<BrowserActionButton>;

  DISALLOW_COPY_AND_ASSIGN(BrowserActionButton);
};


////////////////////////////////////////////////////////////////////////////////
// BrowserActionView
// A single section in the browser action container. This contains the actual
// BrowserActionButton, as well as the logic to paint the badge.

class BrowserActionView : public views::View {
 public:
  BrowserActionView(const Extension* extension, BrowserActionsContainer* panel);
  virtual ~BrowserActionView();

  BrowserActionButton* button() { return button_; }

  // Allocates a canvas object on the heap and draws into it the icon for the
  // view as well as the badge (if any). Caller is responsible for deleting the
  // returned object.
  gfx::Canvas* GetIconWithBadge();

  // Accessibility accessors, overridden from View.
  virtual AccessibilityTypes::Role GetAccessibleRole();

 private:
  virtual void Layout();

  // Override PaintChildren so that we can paint the badge on top of children.
  virtual void PaintChildren(gfx::Canvas* canvas);

  // The container for this view.
  BrowserActionsContainer* panel_;

  // The button this view contains.
  BrowserActionButton* button_;

  DISALLOW_COPY_AND_ASSIGN(BrowserActionView);
};

////////////////////////////////////////////////////////////////////////////////
//
// The BrowserActionsContainer is a container view, responsible for drawing the
// browser action icons (extensions that add icons to the toolbar).
//
// The container is placed flush against the omnibox and wrench menu, and its
// layout looks like:
//   rI_I_IcCs
// Where the letters are as follows:
//   r: An invisible resize area.  This is ToolbarView::kStandardSpacing pixels
//      wide and directly adjacent to the omnibox.
//   I: An icon.  This is as wide as the IDR_BROWSER_ACTION image.
//   _: kItemSpacing pixels of empty space.
//   c: kChevronSpacing pixels of empty space.  Only present if C is present.
//   C: An optional chevron, visible for overflow.  As wide as the
//      IDR_BROWSER_ACTIONS_OVERFLOW image.
//   s: ToolbarView::kStandardSpacing pixels of empty space (before the wrench
//      menu).
// The reason the container contains the trailing space "s", rather than having
// it be handled by the parent view, is so that when the chevron is invisible
// and the user starts dragging an icon around, we have the space to draw the
// ultimate drop indicator.  (Otherwise, we'd be trying to draw it into the
// padding beyond our right edge, and it wouldn't appear.)
//
// The BrowserActionsContainer follows a few rules, in terms of user experience:
//
// 1) The container can never grow beyond the space needed to show all icons
// (hereby referred to as the max width).
// 2) The container can never shrink below the space needed to show just the
// initial padding and the chevron (ignoring the case where there are no icons
// to show, in which case the container won't be visible anyway).
// 3) The container snaps into place (to the pixel count that fits the visible
// icons) to make sure there is no wasted space at the edges of the container.
// 4) If the user adds or removes icons (read: installs/uninstalls browser
// actions) we grow and shrink the container as needed - but ONLY if the
// container was at max width to begin with.
// 5) If the container is NOT at max width (has an overflow menu), we respect
// that size when adding and removing icons and DON'T grow/shrink the container.
// This means that new icons (which always appear at the far right) will show up
// in the overflow menu. The install bubble for extensions points to the chevron
// menu in this case.
//
// Resizing the BrowserActionsContainer:
//
// The ResizeArea view sends OnResize messages to the BrowserActionsContainer
// class as the user drags it. This modifies the value for |resize_amount_|.
// That indicates to the container that a resize is in progress and is used to
// calculate the size in GetPreferredSize(), though that function never exceeds
// the defined minimum and maximum size of the container.
//
// When the user releases the mouse (ends the resize), we calculate a target
// size for the container (animation_target_size_), clamp that value to the
// containers min and max and then animate from the *current* position (that the
// user has dragged the view to) to the target size.
//
// Animating the BrowserActionsContainer:
//
// Animations are used when snapping the container to a value that fits all
// visible icons. This can be triggered when the user finishes resizing the
// container or when Browser Actions are added/removed.
//
// We always animate from the current width (container_width_) to the target
// size (animation_target_size_), using |resize_amount| to keep track of the
// animation progress.
//
// NOTE: When adding Browser Actions to a maximum width container (no overflow)
// we make sure to suppress the chevron menu if it wasn't visible. This is
// because we won't have enough space to show the new Browser Action until the
// animation ends and we don't want the chevron to flash into view while we are
// growing the container.
//
////////////////////////////////////////////////////////////////////////////////
class BrowserActionsContainer
    : public views::View,
      public views::ViewMenuDelegate,
      public views::DragController,
      public views::ResizeArea::ResizeAreaDelegate,
      public ui::AnimationDelegate,
      public ExtensionToolbarModel::Observer,
      public BrowserActionOverflowMenuController::Observer,
      public ExtensionContextMenuModel::PopupDelegate,
      public ExtensionPopup::Observer {
 public:
  BrowserActionsContainer(Browser* browser, views::View* owner_view);
  virtual ~BrowserActionsContainer();

  static void RegisterUserPrefs(PrefService* prefs);

  void Init();

  // Get the number of browser actions being displayed.
  int num_browser_actions() const { return browser_action_views_.size(); }

  // Whether we are performing resize animation on the container.
  bool animating() const { return animation_target_size_ > 0; }

  // Returns the chevron, if any.
  const views::View* chevron() const { return chevron_; }

  // Returns the profile this container is associated with.
  Profile* profile() const { return profile_; }

  // Returns the browser this container is associated with.
  Browser* browser() const { return browser_; }

  // Returns the current tab's ID, or -1 if there is no current tab.
  int GetCurrentTabId() const;

  // Get a particular browser action view.
  BrowserActionView* GetBrowserActionViewAt(int index) {
    return browser_action_views_[index];
  }

  // Retrieve the BrowserActionView for |extension|.
  BrowserActionView* GetBrowserActionView(ExtensionAction* action);

  // Update the views to reflect the state of the browser action icons.
  void RefreshBrowserActionViews();

  // Sets up the browser action view vector.
  void CreateBrowserActionViews();

  // Delete all browser action views.
  void DeleteBrowserActionViews();

  // Called when a browser action becomes visible/hidden.
  void OnBrowserActionVisibilityChanged();

  // Returns how many browser actions are visible.
  size_t VisibleBrowserActions() const;

  // Called when the user clicks on the browser action icon.
  void OnBrowserActionExecuted(BrowserActionButton* button,
                               bool inspect_with_devtools);

  // Overridden from views::View:
  virtual gfx::Size GetPreferredSize();
  virtual void Layout();
  virtual void Paint(gfx::Canvas* canvas);
  virtual void ViewHierarchyChanged(bool is_add,
                                    views::View* parent,
                                    views::View* child);
  virtual bool GetDropFormats(
      int* formats, std::set<ui::OSExchangeData::CustomFormat>* custom_formats);
  virtual bool AreDropTypesRequired();
  virtual bool CanDrop(const ui::OSExchangeData& data);
  virtual void OnDragEntered(const views::DropTargetEvent& event);
  virtual int OnDragUpdated(const views::DropTargetEvent& event);
  virtual void OnDragExited();
  virtual int OnPerformDrop(const views::DropTargetEvent& event);
  virtual void OnThemeChanged();
  virtual AccessibilityTypes::Role GetAccessibleRole();

  // Overridden from views::ViewMenuDelegate:
  virtual void RunMenu(View* source, const gfx::Point& pt);

  // Overridden from views::DragController:
  virtual void WriteDragData(View* sender,
                             const gfx::Point& press_pt,
                             ui::OSExchangeData* data);
  virtual int GetDragOperations(View* sender, const gfx::Point& p);
  virtual bool CanStartDrag(View* sender,
                            const gfx::Point& press_pt,
                            const gfx::Point& p);

  // Overridden from ResizeArea::ResizeAreaDelegate:
  virtual void OnResize(int resize_amount, bool done_resizing);

  // Overridden from ui::AnimationDelegate:
  virtual void AnimationProgressed(const ui::Animation* animation);
  virtual void AnimationEnded(const ui::Animation* animation);

  // Overridden from BrowserActionOverflowMenuController::Observer:
  virtual void NotifyMenuDeleted(
      BrowserActionOverflowMenuController* controller);

  // Overridden from ExtensionContextMenuModel::PopupDelegate
  virtual void InspectPopup(ExtensionAction* action);

  // Overriden from ExtensionPopup::Delegate
  virtual void ExtensionPopupIsClosing(ExtensionPopup* popup);

  // Moves a browser action with |id| to |new_index|.
  void MoveBrowserAction(const std::string& extension_id, size_t new_index);

  // Hide the current popup.
  void HidePopup();

  // Simulate a click on a browser action button.  This should only be
  // used by unit tests.
  void TestExecuteBrowserAction(int index);

  // Retrieve the current popup.  This should only be used by unit tests.
  ExtensionPopup* TestGetPopup() { return popup_; }

  // Set how many icons the container should show. This should only be used by
  // unit tests.
  void TestSetIconVisibilityCount(size_t icons);

  // During testing we can disable animations by setting this flag to true,
  // so that the bar resizes instantly, instead of having to poll it while it
  // animates to open/closed status.
  static bool disable_animations_during_testing_;

 private:
  friend class BrowserActionView;  // So it can access IconHeight().
  friend class ShowFolderMenuTask;

  typedef std::vector<BrowserActionView*> BrowserActionViews;

  // Returns the width of an icon, optionally with its padding.
  static int IconWidth(bool include_padding);

  // Returns the height of an icon.
  static int IconHeight();

  // ExtensionToolbarModel::Observer implementation.
  virtual void BrowserActionAdded(const Extension* extension, int index);
  virtual void BrowserActionRemoved(const Extension* extension);
  virtual void BrowserActionMoved(const Extension* extension, int index);
  virtual void ModelLoaded();

  void LoadImages();

  // Sets the initial container width.
  void SetContainerWidth();

  // Closes the overflow menu if open.
  void CloseOverflowMenu();

  // Cancels the timer for showing the drop down menu.
  void StopShowFolderDropMenuTimer();

  // Show the drop down folder after a slight delay.
  void StartShowFolderDropMenuTimer();

  // Show the overflow menu.
  void ShowDropFolder();

  // Sets the drop indicator position (and schedules paint if the position has
  // changed).
  void SetDropIndicator(int x_pos);

  // Given a number of |icons| and whether to |display_chevron|, returns the
  // amount of pixels needed to draw the entire container.  For convenience,
  // callers can set |icons| to -1 to mean "all icons".
  int IconCountToWidth(int icons, bool display_chevron) const;

  // Given a pixel width, returns the number of icons that fit.  (This
  // automatically determines whether a chevron will be needed and includes it
  // in the calculation.)
  size_t WidthToIconCount(int pixels) const;

  // Returns the absolute minimum size you can shrink the container down to and
  // still show it.  This assumes a visible chevron because the only way we
  // would not have a chevron when shrinking down this far is if there were no
  // icons, in which case the container wouldn't be shown at all.
  int ContainerMinSize() const;

  // Animate to the target size (unless testing, in which case we go straight to
  // the target size).  This also saves the target number of visible icons in
  // the pref if we're not off the record.
  void SaveDesiredSizeAndAnimate(ui::Tween::Type type,
                                 size_t num_visible_icons);

  // Returns true if this extension should be shown in this toolbar. This can
  // return false if we are in an incognito window and the extension is disabled
  // for incognito.
  bool ShouldDisplayBrowserAction(const Extension* extension);

  // The vector of browser actions (icons/image buttons for each action). Note
  // that not every BrowserAction in the ToolbarModel will necessarily be in
  // this collection. Some extensions may be disabled in incognito windows.
  BrowserActionViews browser_action_views_;

  Profile* profile_;

  // The Browser object the container is associated with.
  Browser* browser_;

  // The view that owns us.
  views::View* owner_view_;

  // The current popup and the button it came from.  NULL if no popup.
  ExtensionPopup* popup_;

  // The button that triggered the current popup (just a reference to a button
  // from browser_action_views_).
  BrowserActionButton* popup_button_;

  // The model that tracks the order of the toolbar icons.
  ExtensionToolbarModel* model_;

  // The current width of the container.
  int container_width_;

  // The resize area for the container.
  views::ResizeArea* resize_area_;

  // The chevron for accessing the overflow items.
  views::MenuButton* chevron_;

  // The menu to show for the overflow button (chevron). This class manages its
  // own lifetime so that it can stay alive during drag and drop operations.
  BrowserActionOverflowMenuController* overflow_menu_;

  // The animation that happens when the container snaps to place.
  scoped_ptr<ui::SlideAnimation> resize_animation_;

  // Don't show the chevron while animating.
  bool suppress_chevron_;

  // This is used while the user is resizing (and when the animations are in
  // progress) to know how wide the delta is between the current state and what
  // we should draw.
  int resize_amount_;

  // Keeps track of the absolute pixel width the container should have when we
  // are done animating.
  int animation_target_size_;

  // The x position for where to draw the drop indicator. -1 if no indicator.
  int drop_indicator_position_;

  ScopedRunnableMethodFactory<BrowserActionsContainer> task_factory_;

  // Handles delayed showing of the overflow menu when hovering.
  ScopedRunnableMethodFactory<BrowserActionsContainer> show_menu_task_factory_;

  DISALLOW_COPY_AND_ASSIGN(BrowserActionsContainer);
};

#endif  // CHROME_BROWSER_UI_VIEWS_BROWSER_ACTIONS_CONTAINER_H_