fiv-jpegcrop: add middle mouse button dragging

Parasitic gesture code previously discarded from fiv gets to live on.
This commit is contained in:
Přemysl Eric Janouch 2022-08-10 12:21:57 +02:00
parent 973c024abe
commit 9c9453172a
Signed by: p
GPG Key ID: A0420B94F92B9493

View File

@ -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);