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messing around with gtk
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#include <gtk/gtk.h> | |
#include <stdbool.h> | |
typedef struct ggtkwindow *GGTKWindow; | |
// GGtkWindow GObject declaration | |
#define GGTK_TYPE_WINDOW ggtk_window_get_type() | |
G_DECLARE_FINAL_TYPE(GGtkWindow, ggtk_window, GGTK, WINDOW, GtkLayout) | |
struct _GGtkWindowClass | |
{ | |
GtkLayoutClass parent_class; | |
// virtual methods here, no pad because screw ABI compat, it's internal | |
}; | |
GtkWidget* ggtk_window_new(GGTKWindow gw); | |
GGTKWindow ggtk_window_get_base(GGtkWindow *ggw); | |
void ggtk_window_set_background(GGtkWindow *ggw, GdkRGBA col); | |
cairo_t* ggtk_window_get_cairo_context(GGtkWindow *ggw); | |
void ggtk_window_request_expose(GGtkWindow *ggw, cairo_rectangle_int_t *area); | |
// end GGtkWindow declaration | |
// GGtkWindow definition | |
struct _GGtkWindow | |
{ | |
GtkLayout parent_instance; | |
// private data | |
GGTKWindow gw; | |
GdkRGBA background_color; | |
cairo_surface_t *offscreen_surface; | |
cairo_t* offscreen_context; | |
cairo_region_t* dirty_regions; | |
int offscreen_width; | |
int offscreen_height; | |
bool disposed; | |
}; | |
static void ggtk_window_dispose(GObject *gobject) | |
{ | |
GGtkWindow *ggw = GGTK_WINDOW(gobject); | |
ggw->disposed = true; | |
if (ggw->offscreen_context) { | |
cairo_destroy(ggw->offscreen_context); | |
ggw->offscreen_context = NULL; | |
} | |
if (ggw->dirty_regions) { | |
cairo_region_destroy(ggw->dirty_regions); | |
ggw->dirty_regions = NULL; | |
} | |
if (ggw->offscreen_surface) { | |
cairo_surface_destroy(ggw->offscreen_surface); | |
ggw->offscreen_surface = NULL; | |
} | |
ggw->offscreen_width = 0; | |
ggw->offscreen_height = 0; | |
// Invoke close event on window? | |
} | |
static void ggtk_window_class_init(GGtkWindowClass *ggwc) | |
{ | |
GObjectClass *object_class = G_OBJECT_CLASS(ggwc); | |
object_class->dispose = ggtk_window_dispose; | |
} | |
static void ggtk_window_init(GGtkWindow *ggw) | |
{ | |
(void)ggw; | |
} | |
static gboolean ggtk_window_draw_callback(GtkWidget* widget, cairo_t* cr, G_GNUC_UNUSED gpointer data) | |
{ | |
GGtkWindow *ggw = GGTK_WINDOW(widget); | |
bool repaint_all = false; | |
int width = gtk_widget_get_allocated_width(widget); | |
int height = gtk_widget_get_allocated_height(widget); | |
if (ggw->offscreen_context) { | |
cairo_destroy(ggw->offscreen_context); | |
ggw->offscreen_context = NULL; | |
printf("context destroyed"); | |
} | |
if (!ggw->offscreen_surface || ggw->offscreen_width != width || ggw->offscreen_height != height) { | |
GdkWindow* window = gtk_widget_get_window(widget); | |
cairo_surface_destroy(ggw->offscreen_surface); | |
if (ggw->dirty_regions) { | |
cairo_region_destroy(ggw->dirty_regions); | |
ggw->dirty_regions = NULL; | |
} | |
ggw->offscreen_surface = gdk_window_create_similar_surface(window, CAIRO_CONTENT_COLOR, width, height); | |
ggw->offscreen_width = width; | |
ggw->offscreen_height = height; | |
repaint_all = true; | |
} | |
if (repaint_all || ggw->dirty_regions) { | |
printf("dirty regions"); | |
ggw->offscreen_context = cairo_create(ggw->offscreen_surface); | |
if (ggw->dirty_regions) { | |
cairo_rectangle_int_t area; | |
int num_rectangles = cairo_region_num_rectangles(ggw->dirty_regions); | |
for (int i = 0; i < num_rectangles; ++i) { | |
cairo_region_get_rectangle(ggw->dirty_regions, i, &area); | |
cairo_rectangle(ggw->offscreen_context, area.x, area.y, area.width, area.height); | |
cairo_clip(ggw->offscreen_context); | |
} | |
cairo_region_destroy(ggw->dirty_regions); | |
ggw->dirty_regions = NULL; | |
} | |
cairo_set_operator(ggw->offscreen_context, CAIRO_OPERATOR_SOURCE); | |
cairo_set_source_rgba(ggw->offscreen_context, | |
ggw->background_color.red, ggw->background_color.green, ggw->background_color.red, ggw->background_color.alpha); | |
cairo_paint(ggw->offscreen_context); | |
cairo_set_operator(ggw->offscreen_context, CAIRO_OPERATOR_OVER); | |
// Now call the GDraw expose event handler here | |
cairo_destroy(ggw->offscreen_context); | |
ggw->offscreen_context = NULL; | |
} | |
// Now paint the offscreen surface | |
cairo_set_operator(cr, CAIRO_OPERATOR_SOURCE); // can't do this if it's not opaque | |
cairo_set_source_surface(cr, ggw->offscreen_surface, 0, 0); | |
cairo_paint(cr); | |
return false; | |
} | |
static gboolean ggtk_window_motion_callback (GtkWidget *widget, GdkEventMotion *event, gpointer user_data) | |
{ | |
static GdkPoint points[1000] = {0}; | |
static int i = 0; | |
if (event->state & GDK_BUTTON1_MASK && i < 1000) | |
{ | |
points[i].x = (int)event->x; | |
points[i].y = (int)event->y; | |
i++; | |
cairo_t *cr = ggtk_window_get_cairo_context(GGTK_WINDOW(widget)); | |
if (cr != NULL) | |
{ | |
printf("YeS %d", i); | |
cairo_set_source_rgb(cr, 0,0,0); | |
cairo_set_line_width(cr, 0.5); | |
cairo_move_to(cr, points[0].x, points[0].y); | |
for (int j = 1; j < i; j++) { | |
cairo_line_to(cr, points[j].x, points[j].y); | |
} | |
cairo_stroke(cr); | |
} | |
} | |
fflush(stdout); | |
return false; | |
} | |
GtkWidget* ggtk_window_new(GGTKWindow gw) | |
{ | |
GGtkWindow *ggw = GGTK_WINDOW(g_object_new(GGTK_TYPE_WINDOW, NULL)); | |
g_return_val_if_fail(ggw != NULL, NULL); | |
// I don't know if this is the correct thing to do, how is this meant to | |
// get initialised in the _init method?! | |
ggw->gw = gw; | |
gtk_widget_set_events(GTK_WIDGET(ggw), GDK_POINTER_MOTION_MASK|GDK_BUTTON_PRESS_MASK); | |
g_signal_connect(ggw, "draw", G_CALLBACK(ggtk_window_draw_callback), NULL); | |
g_signal_connect(ggw, "motion-notify-event", G_CALLBACK(ggtk_window_motion_callback), NULL); | |
return GTK_WIDGET(ggw); | |
} | |
GGTKWindow ggtk_window_get_base(GGtkWindow *ggw) | |
{ | |
g_return_val_if_fail(ggw != NULL, NULL); | |
return ggw->gw; | |
} | |
void ggtk_window_set_background(GGtkWindow *ggw, GdkRGBA col) | |
{ | |
ggw->background_color = col; | |
gtk_widget_queue_draw(GTK_WIDGET(ggw)); | |
} | |
cairo_t* ggtk_window_get_cairo_context(GGtkWindow *ggw) | |
{ | |
if (ggw->offscreen_context) { | |
return ggw->offscreen_context; | |
} else if (!ggw->offscreen_surface) { | |
return NULL; | |
} | |
printf("cr context created\n"); | |
ggw->offscreen_context = cairo_create(ggw->offscreen_surface); | |
gtk_widget_queue_draw(GTK_WIDGET(ggw)); | |
//cairo_rectangle_int_t r = {.x = 100, .y = 100, .width = 100, .height = 100}; | |
//ggtk_window_request_expose(ggw, &r); | |
return ggw->offscreen_context; | |
} | |
void ggtk_window_request_expose(GGtkWindow *ggw, cairo_rectangle_int_t *area) | |
{ | |
if (area) { | |
if (ggw->dirty_regions) { | |
cairo_region_union_rectangle(ggw->dirty_regions, area); | |
} else { | |
ggw->dirty_regions = cairo_region_create_rectangle(area); | |
} | |
gtk_widget_queue_draw_area(GTK_WIDGET(ggw), area->x, area->y, area->width, area->height); | |
return; | |
} | |
gtk_widget_queue_draw(GTK_WIDGET(ggw)); | |
} | |
G_DEFINE_TYPE(GGtkWindow, ggtk_window, GTK_TYPE_LAYOUT) | |
static void activate(GtkApplication* app, G_GNUC_UNUSED gpointer user_data) | |
{ | |
GtkWidget* window = gtk_application_window_new(app); | |
gtk_window_set_position (GTK_WINDOW(window), GTK_WIN_POS_CENTER); | |
//G_GNUC_BEGIN_IGNORE_DEPRECATIONS | |
//gdk_window_set_debug_updates(true); | |
//G_GNUC_END_IGNORE_DEPRECATIONS | |
gtk_window_set_title(GTK_WINDOW(window), "Window"); | |
gtk_window_set_default_size(GTK_WINDOW(window), 400, 400); | |
GGtkWindow* ggw = GGTK_WINDOW(ggtk_window_new(NULL)); | |
GdkRGBA col = {.red = 1, .alpha = 1}; | |
ggtk_window_set_background(ggw, col); | |
gtk_container_add(GTK_CONTAINER(window), GTK_WIDGET(ggw)); | |
gtk_widget_show_all(window); | |
} | |
int main(int argc, char** argv) | |
{ | |
GtkApplication* app; | |
int status; | |
gtk_init(&argc, &argv); | |
app = gtk_application_new("org.gtk.example", G_APPLICATION_FLAGS_NONE); | |
g_signal_connect(app, "activate", G_CALLBACK(activate), NULL); | |
status = g_application_run(G_APPLICATION(app), argc, argv); | |
g_object_unref(app); | |
return status; | |
} |
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