diff options
Diffstat (limited to 'panels/wacom/cc-drawing-area.c')
| -rw-r--r-- | panels/wacom/cc-drawing-area.c | 182 |
1 files changed, 182 insertions, 0 deletions
diff --git a/panels/wacom/cc-drawing-area.c b/panels/wacom/cc-drawing-area.c new file mode 100644 index 0000000..3f570ad --- /dev/null +++ b/panels/wacom/cc-drawing-area.c @@ -0,0 +1,182 @@ +/* + * Copyright © 2016 Red Hat, Inc. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see <http://www.gnu.org/licenses/>. + * + * Author: Carlos Garnacho <carlosg@gnome.org> + */ + +#include "config.h" +#include <cairo/cairo.h> +#include "cc-drawing-area.h" + +typedef struct _CcDrawingArea CcDrawingArea; + +struct _CcDrawingArea { + GtkDrawingArea parent; + GtkGesture *stylus_gesture; + cairo_surface_t *surface; + cairo_t *cr; +}; + +G_DEFINE_TYPE (CcDrawingArea, cc_drawing_area, GTK_TYPE_DRAWING_AREA) + +static void +ensure_drawing_surface (CcDrawingArea *area, + gint width, + gint height) +{ + if (!area->surface || + cairo_image_surface_get_width (area->surface) != width || + cairo_image_surface_get_height (area->surface) != height) { + cairo_surface_t *surface; + + surface = cairo_image_surface_create (CAIRO_FORMAT_ARGB32, + width, height); + if (area->surface) { + cairo_t *cr; + + cr = cairo_create (surface); + cairo_set_source_surface (cr, area->surface, 0, 0); + cairo_paint (cr); + + cairo_surface_destroy (area->surface); + cairo_destroy (area->cr); + cairo_destroy (cr); + } + + area->surface = surface; + area->cr = cairo_create (surface); + } +} + +static void +cc_drawing_area_map (GtkWidget *widget) +{ + GtkAllocation allocation; + + GTK_WIDGET_CLASS (cc_drawing_area_parent_class)->map (widget); + + gtk_widget_get_allocation (widget, &allocation); + ensure_drawing_surface (CC_DRAWING_AREA (widget), + allocation.width, allocation.height); +} + +static void +cc_drawing_area_unmap (GtkWidget *widget) +{ + CcDrawingArea *area = CC_DRAWING_AREA (widget); + + if (area->cr) { + cairo_destroy (area->cr); + area->cr = NULL; + } + + if (area->surface) { + cairo_surface_destroy (area->surface); + area->surface = NULL; + } + + GTK_WIDGET_CLASS (cc_drawing_area_parent_class)->unmap (widget); +} + +static void +draw_cb (GtkDrawingArea *drawing_area, + cairo_t *cr, + gint width, + gint height, + gpointer user_data) +{ + CcDrawingArea *area = CC_DRAWING_AREA (drawing_area); + + ensure_drawing_surface (area, width, height); + + cairo_set_source_rgb (cr, 1, 1, 1); + cairo_paint (cr); + + cairo_set_source_surface (cr, area->surface, 0, 0); + cairo_paint (cr); + + cairo_set_source_rgb (cr, 0.6, 0.6, 0.6); + cairo_rectangle (cr, 0, 0, width, height); + cairo_stroke (cr); +} + +static void +stylus_down_cb (GtkGestureStylus *gesture, + double x, + double y, + CcDrawingArea *area) +{ + cairo_new_path (area->cr); +} + +static void +stylus_motion_cb (GtkGestureStylus *gesture, + double x, + double y, + CcDrawingArea *area) +{ + GdkDeviceTool *tool; + gdouble pressure; + + tool = gtk_gesture_stylus_get_device_tool (gesture); + gtk_gesture_stylus_get_axis (gesture, + GDK_AXIS_PRESSURE, + &pressure); + + if (gdk_device_tool_get_tool_type (tool) == GDK_DEVICE_TOOL_TYPE_ERASER) { + cairo_set_line_width (area->cr, 10 * pressure); + cairo_set_operator (area->cr, CAIRO_OPERATOR_DEST_OUT); + } else { + cairo_set_line_width (area->cr, 4 * pressure); + cairo_set_operator (area->cr, CAIRO_OPERATOR_SATURATE); + } + + cairo_set_source_rgba (area->cr, 0, 0, 0, pressure); + cairo_line_to (area->cr, x, y); + cairo_stroke (area->cr); + + cairo_move_to (area->cr, x, y); + + gtk_widget_queue_draw (GTK_WIDGET (area)); +} + +static void +cc_drawing_area_class_init (CcDrawingAreaClass *klass) +{ + GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (klass); + + widget_class->map = cc_drawing_area_map; + widget_class->unmap = cc_drawing_area_unmap; +} + +static void +cc_drawing_area_init (CcDrawingArea *area) +{ + gtk_drawing_area_set_draw_func (GTK_DRAWING_AREA (area), draw_cb, NULL, NULL); + area->stylus_gesture = gtk_gesture_stylus_new (); + g_signal_connect (area->stylus_gesture, "down", + G_CALLBACK (stylus_down_cb), area); + g_signal_connect (area->stylus_gesture, "motion", + G_CALLBACK (stylus_motion_cb), area); + gtk_widget_add_controller (GTK_WIDGET (area), + GTK_EVENT_CONTROLLER (area->stylus_gesture)); +} + +GtkWidget * +cc_drawing_area_new (void) +{ + return g_object_new (CC_TYPE_DRAWING_AREA, NULL); +} |