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// Copyright 2016 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.
#include "base/time/time.h"
#include "base/timer/timer.h"
#include "ui/gfx/geometry/point.h"
#include "ui/gfx/range/range.h"
#include "ui/gfx/selection_model.h"
#include "ui/views/views_export.h"
namespace gfx {
class RenderText;
namespace ui {
class MouseEvent;
namespace views {
class SelectionControllerDelegate;
// Helper class used to facilitate mouse event handling and text selection. To
// use, clients must implement the SelectionControllerDelegate interface.
// TODO(karandeepb): Also make this class handle gesture events.
class VIEWS_EXPORT SelectionController {
// Describes whether the view managing the delegate was initially focused when
// the mouse press was received.
enum class InitialFocusStateOnMousePress {
// |delegate| must be non-null.
explicit SelectionController(SelectionControllerDelegate* delegate);
// Handle mouse events forwarded by |delegate_|. |handled| specifies whether
// the event has already been handled by the |delegate_|. If |handled| is
// true, the mouse event is just used to update the internal state without
// updating the state of the associated RenderText instance.
bool OnMousePressed(const ui::MouseEvent& event,
bool handled,
InitialFocusStateOnMousePress initial_focus_state);
bool OnMouseDragged(const ui::MouseEvent& event);
void OnMouseReleased(const ui::MouseEvent& event);
void OnMouseCaptureLost();
// Returns the latest click location in root coordinates.
const gfx::Point& last_click_root_location() const {
return last_click_root_location_;
// Sets whether the SelectionController should update or paste the
// selection clipboard on middle-click. Default is false.
void set_handles_selection_clipboard(bool value) {
handles_selection_clipboard_ = value;
// Offsets the double-clicked word's range. This is only used in the unusual
// case where the text changes on the second mousedown of a double-click.
// This is harmless if there is not a currently double-clicked word.
void OffsetDoubleClickWord(int offset);
// Tracks the mouse clicks for single/double/triple clicks.
void TrackMouseClicks(const ui::MouseEvent& event);
// Selects the word at the given |point|.
void SelectWord(const gfx::Point& point);
// Selects all the text.
void SelectAll();
// Returns the associated render text instance via the |delegate_|.
gfx::RenderText* GetRenderText();
// Helper function to update the selection on a mouse drag as per
// |last_drag_location_|. Can be called asynchronously, through a timer.
void SelectThroughLastDragLocation();
// Returns whether |point| is inside any substring of the text.
bool IsInsideText(const gfx::Point& point);
// A timer and point used to modify the selection when dragging. The
// |first_drag_location_| field is used to store where the drag-to-select
// started.
base::RepeatingTimer drag_selection_timer_;
gfx::Point last_drag_location_;
gfx::Point first_drag_location_;
// State variables used to track the last click time and location.
base::TimeTicks last_click_time_;
gfx::Point last_click_root_location_;
// Used to track double and triple clicks. Can take the values 0, 1 and 2
// which specify a single, double and triple click respectively. Alternates
// between a double and triple click for continuous clicks.
size_t aggregated_clicks_;
// The range selected on a double click.
gfx::Range double_click_word_;
// Weak pointer.
SelectionControllerDelegate* delegate_;
// Whether the selection clipboard is handled.
bool handles_selection_clipboard_;
} // namespace views