From 4efda5347ca1fd06e1edc95b6e5269ba1b10a6bf Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?P=C5=99emysl=20Eric=20Janouch?= Date: Sun, 17 Jul 2022 07:15:19 +0200 Subject: Let FivView take care of its drag gesture Making the GtkScrolledWindow's scrollbars draggable again. --- fiv-view.c | 83 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 79 insertions(+), 4 deletions(-) (limited to 'fiv-view.c') diff --git a/fiv-view.c b/fiv-view.c index 25494b0..1fa4880 100644 --- a/fiv-view.c +++ b/fiv-view.c @@ -68,6 +68,7 @@ struct _FivView { bool enhance : 1; ///< Try to enhance picture data bool scale_to_fit : 1; ///< Image no larger than the allocation double scale; ///< Scaling factor + double drag_start[2]; ///< Adjustment values for drag origin cairo_surface_t *enhance_swap; ///< Quick swap in/out FivIoProfile screen_cms_profile; ///< Target colour profile for widget @@ -489,8 +490,7 @@ fiv_view_realize(GtkWidget *widget) // than what we get automatically. .visual = gtk_widget_get_visual(widget), - // Pointer motion/release enables attaching GtkGestureDrag to - // the parent GtkScrolledWindow, having it work with the mouse. + // Pointer motion/release enables GtkGestureDrag. .event_mask = gtk_widget_get_events(widget) | GDK_KEY_PRESS_MASK | GDK_SCROLL_MASK | GDK_BUTTON_PRESS_MASK | GDK_BUTTON_RELEASE_MASK | GDK_POINTER_MOTION_MASK, @@ -621,13 +621,12 @@ fiv_view_draw(GtkWidget *widget, cairo_t *cr) static gboolean fiv_view_button_press_event(GtkWidget *widget, GdkEventButton *event) { + // XXX: Return value? GTK_WIDGET_CLASS(fiv_view_parent_class)->button_press_event(widget, event); if (event->button == GDK_BUTTON_PRIMARY && gtk_widget_get_focus_on_click(widget)) gtk_widget_grab_focus(widget); - - // TODO(p): Use for left button scroll drag, which may rather be a gesture. return FALSE; } @@ -829,6 +828,63 @@ fiv_view_unmap(GtkWidget *widget) // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - +static void +on_drag_begin(GtkGestureDrag *drag, G_GNUC_UNUSED gdouble start_x, + G_GNUC_UNUSED gdouble start_y, gpointer user_data) +{ + GtkGesture *gesture = GTK_GESTURE(drag); + GdkEventSequence *sequence = gtk_gesture_get_last_updated_sequence(gesture); + GdkModifierType state = 0; + gdk_event_get_state(gtk_gesture_get_last_event(gesture, sequence), &state); + if (state & gtk_accelerator_get_default_mod_mask()) { + gtk_gesture_set_state(gesture, GTK_EVENT_SEQUENCE_DENIED); + return; + } + + // Since we set this up as a pointer-only gesture, there is only the NULL + // sequence, so gtk_gesture_set_sequence_state() is completely unneeded. + gtk_gesture_set_state(gesture, GTK_EVENT_SEQUENCE_CLAIMED); + + GdkWindow *window = gtk_widget_get_window( + gtk_event_controller_get_widget(GTK_EVENT_CONTROLLER(drag))); + GdkCursor *cursor = + gdk_cursor_new_from_name(gdk_window_get_display(window), "grabbing"); + gdk_window_set_cursor(window, cursor); + g_object_unref(cursor); + + FivView *self = FIV_VIEW(user_data); + self->drag_start[0] = self->hadjustment ? + gtk_adjustment_get_value(self->hadjustment) : 0; + self->drag_start[1] = self->vadjustment ? + gtk_adjustment_get_value(self->vadjustment) : 0; +} + +static void +on_drag_update(G_GNUC_UNUSED GtkGestureDrag *drag, gdouble offset_x, + gdouble offset_y, gpointer user_data) +{ + FivView *self = FIV_VIEW(user_data); + if (self->hadjustment) { + gtk_adjustment_set_value( + self->hadjustment, self->drag_start[0] - offset_x); + } + if (self->vadjustment) { + gtk_adjustment_set_value( + self->vadjustment, self->drag_start[1] - offset_y); + } +} + +static void +on_drag_end(GtkGestureDrag *drag, G_GNUC_UNUSED gdouble start_x, + G_GNUC_UNUSED gdouble start_y, G_GNUC_UNUSED gpointer user_data) +{ + GdkWindow *window = gtk_widget_get_window( + gtk_event_controller_get_widget(GTK_EVENT_CONTROLLER(drag))); + gdk_window_set_cursor(window, NULL); +} + +// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - + static void show_error_dialog(GtkWindow *parent, GError *error) { @@ -1275,6 +1331,25 @@ fiv_view_init(FivView *self) self->filter = true; self->checkerboard = false; self->scale = 1.0; + + GtkGesture *drag = gtk_gesture_drag_new(GTK_WIDGET(self)); + g_object_set_data_full( + G_OBJECT(self), "fiv-view-drag-gesture", drag, g_object_unref); + gtk_event_controller_set_propagation_phase( + GTK_EVENT_CONTROLLER(drag), GTK_PHASE_BUBBLE); + + // GtkScrolledWindow's internal GtkGestureDrag is set to only look for + // touch events (and its "event_controllers" are perfectly private, + // so we can't change this), hopefully this is mutually exclusive with that. + // Though note that the GdkWindow doesn't register for touch events now. + gtk_gesture_single_set_exclusive(GTK_GESTURE_SINGLE(drag), TRUE); + + g_signal_connect(drag, "drag-begin", + G_CALLBACK(on_drag_begin), self); + g_signal_connect(drag, "drag-update", + G_CALLBACK(on_drag_update), self); + g_signal_connect(drag, "drag-end", + G_CALLBACK(on_drag_end), self); } // --- Public interface -------------------------------------------------------- -- cgit v1.2.3