From 9c9453172a3941b6e43ceac0f86ecd96ead1ffb2 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?P=C5=99emysl=20Eric=20Janouch?= Date: Wed, 10 Aug 2022 12:21:57 +0200 Subject: fiv-jpegcrop: add middle mouse button dragging Parasitic gesture code previously discarded from fiv gets to live on. --- fiv-jpegcrop.c | 74 ++++++++++++++++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 69 insertions(+), 5 deletions(-) diff --git a/fiv-jpegcrop.c b/fiv-jpegcrop.c index 12d0981..fad0c22 100644 --- a/fiv-jpegcrop.c +++ b/fiv-jpegcrop.c @@ -267,6 +267,56 @@ on_motion(G_GNUC_UNUSED GtkWidget *self, GdkEventMotion *event, return FALSE; } +static void +on_drag_begin( + GtkGestureDrag *self, gdouble start_x, gdouble start_y, gpointer user_data) +{ + // The middle mouse button will never be triggered by touch screens, + // so there is only the NULL sequence to care about. + gtk_gesture_set_state(GTK_GESTURE(self), GTK_EVENT_SEQUENCE_CLAIMED); + + GdkWindow *window = gtk_widget_get_window(g.view); + GdkCursor *cursor = + gdk_cursor_new_from_name(gdk_window_get_display(window), "grabbing"); + gdk_window_set_cursor(window, cursor); + g_object_unref(cursor); + + double *last = user_data; + last[0] = start_x; + last[1] = start_y; +} + +static void +on_drag_update(GtkGestureDrag *self, gdouble offset_x, gdouble offset_y, + gpointer user_data) +{ + double start_x = 0, start_y = 0; + gtk_gesture_drag_get_start_point(self, &start_x, &start_y); + + double *last = user_data, + diff_x = (start_x + offset_x) - last[0], + diff_y = (start_y + offset_y) - last[1]; + + last[0] = start_x + offset_x; + last[1] = start_y + offset_y; + + GtkScrolledWindow *sw = GTK_SCROLLED_WINDOW(g.scrolled); + GtkAdjustment *h = gtk_scrolled_window_get_hadjustment(sw); + GtkAdjustment *v = gtk_scrolled_window_get_vadjustment(sw); + if (diff_x) + gtk_adjustment_set_value(h, gtk_adjustment_get_value(h) - diff_x); + if (diff_y) + gtk_adjustment_set_value(v, gtk_adjustment_get_value(v) - diff_y); +} + +static void +on_drag_end(G_GNUC_UNUSED GtkGestureDrag *self, G_GNUC_UNUSED gdouble start_x, + G_GNUC_UNUSED gdouble start_y, G_GNUC_UNUSED gpointer user_data) +{ + // Cursors follow the widget hierarchy. + gdk_window_set_cursor(gtk_widget_get_window(g.view), NULL); +} + static gboolean open_jpeg(const char *data, gsize len, GError **error) { @@ -405,15 +455,16 @@ main(int argc, char *argv[]) g.view = gtk_drawing_area_new(); gtk_widget_set_size_request(g.view, g.width + 2, g.height + 2); - gtk_widget_add_events( - g.view, GDK_BUTTON_PRESS_MASK | GDK_POINTER_MOTION_MASK); - g_signal_connect(g.view, "draw", G_CALLBACK(on_draw), NULL); + gtk_widget_add_events(g.view, + GDK_BUTTON_PRESS_MASK | GDK_BUTTON_RELEASE_MASK | + GDK_POINTER_MOTION_MASK); + g_signal_connect(g.view, "draw", + G_CALLBACK(on_draw), NULL); g_signal_connect(g.view, "button-press-event", G_CALLBACK(on_press), NULL); g_signal_connect(g.view, "motion-notify-event", G_CALLBACK(on_motion), NULL); - // TODO(p): Track middle mouse button drags, adjust the adjustments. g.scrolled = gtk_scrolled_window_new(NULL, NULL); gtk_scrolled_window_set_overlay_scrolling( GTK_SCROLLED_WINDOW(g.scrolled), FALSE); @@ -422,13 +473,26 @@ main(int argc, char *argv[]) gtk_scrolled_window_set_propagate_natural_height( GTK_SCROLLED_WINDOW(g.scrolled), TRUE); + GtkGesture *drag = gtk_gesture_drag_new(g.scrolled); + gtk_event_controller_set_propagation_phase( + GTK_EVENT_CONTROLLER(drag), GTK_PHASE_CAPTURE); + gtk_gesture_single_set_button(GTK_GESTURE_SINGLE(drag), GDK_BUTTON_MIDDLE); + + double last_drag_point[2] = {}; + g_signal_connect(drag, "drag-begin", + G_CALLBACK(on_drag_begin), last_drag_point); + g_signal_connect(drag, "drag-update", + G_CALLBACK(on_drag_update), last_drag_point); + g_signal_connect(drag, "drag-end", + G_CALLBACK(on_drag_end), last_drag_point); + gtk_container_add(GTK_CONTAINER(g.scrolled), g.view); gtk_container_add(GTK_CONTAINER(g.window), g.scrolled); gtk_window_set_default_size(GTK_WINDOW(g.window), 800, 600); gtk_widget_show_all(g.window); // It probably needs to be realized. - GdkWindow *window = gtk_widget_get_window(g.view); + GdkWindow *window = gtk_widget_get_window(g.scrolled); GdkCursor *cursor = gdk_cursor_new_from_name(gdk_window_get_display(window), "crosshair"); gdk_window_set_cursor(window, cursor); -- cgit v1.2.3