// Copyright 2025 The Chromium Authors // 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_FRAME_MULTI_CONTENTS_VIEW_DROP_TARGET_CONTROLLER_H_ #define CHROME_BROWSER_UI_VIEWS_FRAME_MULTI_CONTENTS_VIEW_DROP_TARGET_CONTROLLER_H_ #include #include "base/callback_list.h" #include "base/time/time.h" #include "base/timer/timer.h" #include "chrome/browser/ui/tabs/tab_strip_model.h" #include "chrome/browser/ui/tabs/tab_strip_model_observer.h" #include "chrome/browser/ui/views/frame/multi_contents_drop_target_view.h" #include "chrome/browser/ui/views/tabs/dragging/tab_drag_target.h" #include "components/prefs/pref_change_registrar.h" #include "ui/base/interaction/element_identifier.h" #include "ui/views/view.h" namespace content { struct DropData; } // namespace content class PrefService; class TabStripModel; // `MultiContentsViewDropTargetController` is responsible for handling // the drag-entrypoint of a single `MultiContentsView`. This includes dragging // links, bookmarks, or tab headers to create a split view. // There exists one `MultiContentsViewDropTargetController` per // `MultiContentesView`. class MultiContentsViewDropTargetController final : public TabDragTarget, public MultiContentsDropTargetView::DragDelegate, public TabStripModelObserver { public: static constexpr base::TimeDelta kShowDropTargetForLinkDelay = base::Milliseconds(500); static constexpr base::TimeDelta kShowDropTargetForLinkAfterHideDelay = base::Milliseconds(3000); static constexpr double kNudgeShowRatio = 0.4; static constexpr int kNudgeShownLimit = 6; static constexpr int kNudgeUsedLimit = 1; struct DropTargetConstants { static int GetHideWidth(); static double GetHidePercentage(); }; // Delegate for handling the drop callback. class DropDelegate { public: virtual ~DropDelegate() = default; // Handles links that are dropped on the view. virtual void HandleLinkDrop(MultiContentsDropTargetView::DropSide side, const ui::DropTargetEvent& event) = 0; // Handles tabs that are dropped on the view. virtual void HandleTabDrop(MultiContentsDropTargetView::DropSide side, TabDragTarget::DragController& controller) = 0; }; MultiContentsViewDropTargetController( MultiContentsDropTargetView& drop_target_view, DropDelegate& drop_delegate, PrefService* prefs, TabStripModel* tab_strip_model); ~MultiContentsViewDropTargetController() override; MultiContentsViewDropTargetController( const MultiContentsViewDropTargetController&) = delete; MultiContentsViewDropTargetController& operator=( const MultiContentsViewDropTargetController&) = delete; // TabDragTarget TabDragContext* OnTabDragUpdated(TabDragTarget::DragController& controller, const gfx::Point& point_in_screen) override; void OnTabDragEntered() override; void OnTabDragExited(const gfx::Point& point_in_screen) override; void OnTabDragEnded() override; bool CanDropTab() override; void HandleTabDrop(TabDragTarget::DragController& controller) override; base::CallbackListSubscription RegisterWillDestroyCallback( base::OnceClosure callback) override; // Handles a drag within the web contents area. // `point` should be relative to the multi contents view. void OnWebContentsDragUpdate(const content::DropData& data, const gfx::Point& point, bool is_in_split_view); void OnWebContentsDragExit(); void OnWebContentsDragEnded(); // MultiContentsDropTargetView::DragDelegate: bool GetDropFormats(int* formats, std::set* format_types) override; bool CanDrop(const ui::OSExchangeData& data) override; void OnDragExited() override; void OnDragDone() override; void OnDragEntered(const ui::DropTargetEvent& event) override; int OnDragUpdated(const ui::DropTargetEvent& event) override; views::View::DropCallback GetDropCallback( const ui::DropTargetEvent& event) override; // TabStripModelObserver: void OnTabStripModelChanged( TabStripModel* tab_strip_model, const TabStripModelChange& change, const TabStripSelectionChange& selection) override; bool IsDropTimerRunningForTesting(); private: void DoDrop(const ui::DropTargetEvent& event, ui::mojom::DragOperation& output_drag_op, std::unique_ptr drag_image_layer_owner); // Represents a timer for delaying when a specific drop target view is shown. struct DropTargetShowTimer { DropTargetShowTimer(MultiContentsDropTargetView::DropSide drop_side, MultiContentsDropTargetView::DragType drag_type); base::OneShotTimer timer; MultiContentsDropTargetView::DropSide drop_side; MultiContentsDropTargetView::DragType drag_type; }; // Updates the timers for a drag at the given point. // Assumes the dragged data is droppable (e.g. tab or link). void HandleDragUpdate(const gfx::Point& point_in_view, MultiContentsDropTargetView::DragType drag_type); // Starts or updates a running timer to show `target_to_show`. void StartOrUpdateDropTargetTimer( const gfx::Point& point_in_view, int drop_entry_point_size, MultiContentsDropTargetView::DropSide drop_side, MultiContentsDropTargetView::DragType drag_type); void ResetDropTargetTimers(); // Shows the drop target that should be displayed at the end of the delay. void ShowTimerDelayedDropTarget(); // Timer to hide the drop target if the drag isn't over web contents or // drop target. void StartDropTargetHideTimer(); // Hide the drop target view. void HideDropTarget(bool suppress_animation = false); // Timer to show the nudge after a small delay. void StartNudgeShowTimer(MultiContentsDropTargetView::DropSide drop_side); // Actually show the drop target nudge. void ShowTimerDelayedNudge(MultiContentsDropTargetView::DropSide drop_side); // Used to determine if the drop target should be hidden because the OS drop // target would be visible. Estimation based on when OS drop targets typically // show. bool PointOverlapsWithOSDropTarget(const gfx::Point& point_in_screen); // Keeps the value of nudge_shown_count_ in sync with the pref. void OnDragAndDropNudgeShownCountChange(); // Keeps the value of nudge_used_count_ in sync with the pref. void OnDragAndDropNudgeUsedCountChange(); // Whether the nudge should be shown, based on the number of times it has been // shown/used in the past. bool ShouldShowNudge(); // This timer is used for showing the drop target a delay, and may be // canceled in case a drag exits the drop area before the target is shown. std::optional show_drop_target_timer_; base::OneShotTimer hide_drop_target_timer_; std::optional show_nudge_timer_; // Stores the most recent time the drop target was hidden. Used to calculate // the show timer for link drags. base::Time drop_target_last_hidden_; // The view that is displayed when drags hover over the "drop" region of // the content area. const raw_ref drop_target_view_; const raw_ref drop_target_parent_view_; const raw_ref drop_delegate_; base::OnceClosureList on_will_destroy_callback_list_; // Used to read/write the nudge count pref. raw_ptr prefs_; PrefChangeRegistrar pref_change_registrar_; // Tracks the value of prefs::kSplitViewDragAndDropNudgeShownCount. int nudge_shown_count_; // Tracks the value of prefs::kSplitViewDragAndDropNudgeUsedCount. int nudge_used_count_; // The last point where the drag was updated while in the drop area. gfx::Point drag_point_at_timer_start_; base::ScopedObservation tab_strip_model_observer_{this}; }; #endif // CHROME_BROWSER_UI_VIEWS_FRAME_MULTI_CONTENTS_VIEW_DROP_TARGET_CONTROLLER_H_