| // Copyright 2013 The Flutter 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 "flutter/shell/platform/linux/fl_scrolling_manager.h" |
| |
| static constexpr int kMicrosecondsPerMillisecond = 1000; |
| |
| struct _FlScrollingManager { |
| GObject parent_instance; |
| |
| FlScrollingViewDelegate* view_delegate; |
| |
| gdouble last_x; |
| gdouble last_y; |
| |
| gboolean pan_started; |
| gdouble pan_x; |
| gdouble pan_y; |
| |
| gboolean zoom_started; |
| gboolean rotate_started; |
| gdouble scale; |
| gdouble rotation; |
| }; |
| |
| G_DEFINE_TYPE(FlScrollingManager, fl_scrolling_manager, G_TYPE_OBJECT); |
| |
| static void fl_scrolling_manager_dispose(GObject* object) { |
| FlScrollingManager* self = FL_SCROLLING_MANAGER(object); |
| |
| if (self->view_delegate != nullptr) { |
| g_object_remove_weak_pointer( |
| object, reinterpret_cast<gpointer*>(&self->view_delegate)); |
| self->view_delegate = nullptr; |
| } |
| |
| G_OBJECT_CLASS(fl_scrolling_manager_parent_class)->dispose(object); |
| } |
| |
| static void fl_scrolling_manager_class_init(FlScrollingManagerClass* klass) { |
| G_OBJECT_CLASS(klass)->dispose = fl_scrolling_manager_dispose; |
| } |
| |
| static void fl_scrolling_manager_init(FlScrollingManager* self) {} |
| |
| FlScrollingManager* fl_scrolling_manager_new( |
| FlScrollingViewDelegate* view_delegate) { |
| g_return_val_if_fail(FL_IS_SCROLLING_VIEW_DELEGATE(view_delegate), nullptr); |
| |
| FlScrollingManager* self = FL_SCROLLING_MANAGER( |
| g_object_new(fl_scrolling_manager_get_type(), nullptr)); |
| |
| self->view_delegate = view_delegate; |
| g_object_add_weak_pointer( |
| G_OBJECT(view_delegate), |
| reinterpret_cast<gpointer*>(&(self->view_delegate))); |
| |
| self->pan_started = FALSE; |
| self->zoom_started = FALSE; |
| self->rotate_started = FALSE; |
| |
| return self; |
| } |
| |
| void fl_scrolling_manager_set_last_mouse_position(FlScrollingManager* self, |
| gdouble x, |
| gdouble y) { |
| g_return_if_fail(FL_IS_SCROLLING_MANAGER(self)); |
| self->last_x = x; |
| self->last_y = y; |
| } |
| |
| void fl_scrolling_manager_handle_scroll_event(FlScrollingManager* self, |
| GdkEventScroll* scroll_event, |
| gint scale_factor) { |
| g_return_if_fail(FL_IS_SCROLLING_MANAGER(self)); |
| |
| GdkEvent* event = reinterpret_cast<GdkEvent*>(scroll_event); |
| |
| guint event_time = gdk_event_get_time(event); |
| gdouble event_x = 0.0, event_y = 0.0; |
| gdk_event_get_coords(event, &event_x, &event_y); |
| gdouble scroll_delta_x = 0.0, scroll_delta_y = 0.0; |
| GdkScrollDirection event_direction = GDK_SCROLL_SMOOTH; |
| if (gdk_event_get_scroll_direction(event, &event_direction)) { |
| if (event_direction == GDK_SCROLL_UP) { |
| scroll_delta_x = 0; |
| scroll_delta_y = -1; |
| } else if (event_direction == GDK_SCROLL_DOWN) { |
| scroll_delta_x = 0; |
| scroll_delta_y = 1; |
| } else if (event_direction == GDK_SCROLL_LEFT) { |
| scroll_delta_x = -1; |
| scroll_delta_y = 0; |
| } else if (event_direction == GDK_SCROLL_RIGHT) { |
| scroll_delta_x = 1; |
| scroll_delta_y = 0; |
| } |
| } else { |
| gdk_event_get_scroll_deltas(event, &scroll_delta_x, &scroll_delta_y); |
| } |
| |
| // The multiplier is taken from the Chromium source |
| // (ui/events/x/events_x_utils.cc). |
| const int kScrollOffsetMultiplier = 53; |
| scroll_delta_x *= kScrollOffsetMultiplier * scale_factor; |
| scroll_delta_y *= kScrollOffsetMultiplier * scale_factor; |
| |
| if (gdk_device_get_source(gdk_event_get_source_device(event)) == |
| GDK_SOURCE_TOUCHPAD) { |
| scroll_delta_x *= -1; |
| scroll_delta_y *= -1; |
| if (gdk_event_is_scroll_stop_event(event)) { |
| fl_scrolling_view_delegate_send_pointer_pan_zoom_event( |
| self->view_delegate, event_time * kMicrosecondsPerMillisecond, |
| event_x * scale_factor, event_y * scale_factor, kPanZoomEnd, |
| self->pan_x, self->pan_y, 0, 0); |
| self->pan_started = FALSE; |
| } else { |
| if (!self->pan_started) { |
| self->pan_x = 0; |
| self->pan_y = 0; |
| fl_scrolling_view_delegate_send_pointer_pan_zoom_event( |
| self->view_delegate, event_time * kMicrosecondsPerMillisecond, |
| event_x * scale_factor, event_y * scale_factor, kPanZoomStart, 0, 0, |
| 0, 0); |
| self->pan_started = TRUE; |
| } |
| self->pan_x += scroll_delta_x; |
| self->pan_y += scroll_delta_y; |
| fl_scrolling_view_delegate_send_pointer_pan_zoom_event( |
| self->view_delegate, event_time * kMicrosecondsPerMillisecond, |
| event_x * scale_factor, event_y * scale_factor, kPanZoomUpdate, |
| self->pan_x, self->pan_y, 1, 0); |
| } |
| } else { |
| self->last_x = event_x * scale_factor; |
| self->last_y = event_y * scale_factor; |
| fl_scrolling_view_delegate_send_mouse_pointer_event( |
| self->view_delegate, |
| FlutterPointerPhase::kMove /* arbitrary value, phase will be ignored as |
| this is a discrete scroll event */ |
| , |
| event_time * kMicrosecondsPerMillisecond, event_x * scale_factor, |
| event_y * scale_factor, scroll_delta_x, scroll_delta_y, 0); |
| } |
| } |
| |
| void fl_scrolling_manager_handle_rotation_begin(FlScrollingManager* self) { |
| g_return_if_fail(FL_IS_SCROLLING_MANAGER(self)); |
| |
| self->rotate_started = TRUE; |
| if (!self->zoom_started) { |
| self->scale = 1; |
| self->rotation = 0; |
| fl_scrolling_view_delegate_send_pointer_pan_zoom_event( |
| self->view_delegate, g_get_real_time(), self->last_x, self->last_y, |
| kPanZoomStart, 0, 0, 0, 0); |
| } |
| } |
| |
| void fl_scrolling_manager_handle_rotation_update(FlScrollingManager* self, |
| gdouble rotation) { |
| g_return_if_fail(FL_IS_SCROLLING_MANAGER(self)); |
| |
| self->rotation = rotation; |
| fl_scrolling_view_delegate_send_pointer_pan_zoom_event( |
| self->view_delegate, g_get_real_time(), self->last_x, self->last_y, |
| kPanZoomUpdate, 0, 0, self->scale, self->rotation); |
| } |
| |
| void fl_scrolling_manager_handle_rotation_end(FlScrollingManager* self) { |
| g_return_if_fail(FL_IS_SCROLLING_MANAGER(self)); |
| |
| self->rotate_started = FALSE; |
| if (!self->zoom_started) { |
| fl_scrolling_view_delegate_send_pointer_pan_zoom_event( |
| self->view_delegate, g_get_real_time(), self->last_x, self->last_y, |
| kPanZoomEnd, 0, 0, 0, 0); |
| } |
| } |
| |
| void fl_scrolling_manager_handle_zoom_begin(FlScrollingManager* self) { |
| g_return_if_fail(FL_IS_SCROLLING_MANAGER(self)); |
| |
| self->zoom_started = TRUE; |
| if (!self->rotate_started) { |
| self->scale = 1; |
| self->rotation = 0; |
| fl_scrolling_view_delegate_send_pointer_pan_zoom_event( |
| self->view_delegate, g_get_real_time(), self->last_x, self->last_y, |
| kPanZoomStart, 0, 0, 0, 0); |
| } |
| } |
| |
| void fl_scrolling_manager_handle_zoom_update(FlScrollingManager* self, |
| gdouble scale) { |
| g_return_if_fail(FL_IS_SCROLLING_MANAGER(self)); |
| |
| self->scale = scale; |
| fl_scrolling_view_delegate_send_pointer_pan_zoom_event( |
| self->view_delegate, g_get_real_time(), self->last_x, self->last_y, |
| kPanZoomUpdate, 0, 0, self->scale, self->rotation); |
| } |
| |
| void fl_scrolling_manager_handle_zoom_end(FlScrollingManager* self) { |
| g_return_if_fail(FL_IS_SCROLLING_MANAGER(self)); |
| |
| self->zoom_started = FALSE; |
| if (!self->rotate_started) { |
| fl_scrolling_view_delegate_send_pointer_pan_zoom_event( |
| self->view_delegate, g_get_real_time(), self->last_x, self->last_y, |
| kPanZoomEnd, 0, 0, 0, 0); |
| } |
| } |