diff -r 000000000000 -r 804d8803eade ui/gtk/draw_cairo.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ui/gtk/draw_cairo.c	Wed Dec 09 11:32:01 2020 +0100
@@ -0,0 +1,132 @@
+/*
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
+ *
+ * Copyright 2017 Olaf Wintermann. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *   1. Redistributions of source code must retain the above copyright
+ *      notice, this list of conditions and the following disclaimer.
+ *
+ *   2. Redistributions in binary form must reproduce the above copyright
+ *      notice, this list of conditions and the following disclaimer in the
+ *      documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "container.h"
+
+#include "draw_cairo.h"
+
+#ifdef UI_GTK3
+gboolean ui_drawingarea_expose(GtkWidget *w, cairo_t *cr, void *data) {
+    UiCairoGraphics g;
+    g.g.width = gtk_widget_get_allocated_width(w);
+    g.g.height = gtk_widget_get_allocated_height(w);
+    g.widget = w;
+    g.cr = cr;
+    
+    UiDrawEvent *event = data;
+    UiEvent ev;
+    ev.obj = event->obj;
+    ev.window = event->obj->window;
+    ev.document = event->obj->ctx->document;
+    
+    event->callback(&ev, &g.g, event->userdata);
+    
+    return FALSE;
+}
+#else
+gboolean ui_canvas_expose(GtkWidget *w, GdkEventExpose *e, void *data) {
+    UiCairoGraphics g;
+    g.g.width = w->allocation.width;
+    g.g.height = w->allocation.height;
+    g.widget = w;
+    g.cr = gdk_cairo_create(w->window);
+    
+    UiDrawEvent *event = data;
+    UiEvent ev;
+    ev.obj = event->obj;
+    ev.window = event->obj->window;
+    ev.document = event->obj->ctx->document;
+    
+    event->callback(&ev, &g.g, event->userdata);
+    
+    return FALSE;
+}
+#endif
+
+// function from graphics.h
+
+void ui_connect_draw_handler(GtkWidget *widget, UiDrawEvent *event) {
+#ifdef UI_GTK3
+    g_signal_connect(G_OBJECT(widget),
+            "draw",
+            G_CALLBACK(ui_drawingarea_expose),
+            event);
+#else
+    g_signal_connect(G_OBJECT(widget),
+            "expose_event",
+            G_CALLBACK(ui_canvas_expose),
+            event);
+#endif
+}
+
+
+PangoContext *ui_get_pango_context(UiGraphics *g) {
+    UiCairoGraphics *gr = (UiCairoGraphics*)g;
+    //return gtk_widget_get_pango_context(gr->widget);
+    return pango_cairo_create_context(gr->cr);
+}
+
+
+// drawing functions
+void ui_graphics_color(UiGraphics *g, int red, int green, int blue) {
+    UiCairoGraphics *gr = (UiCairoGraphics*)g;
+    double dred = (double)red / (double)255;
+    double dgreen = (double)green / (double)255;
+    double dblue = (double)blue / (double)255;
+    cairo_set_source_rgb(gr->cr, dred, dgreen, dblue);
+}
+
+
+void ui_draw_line(UiGraphics *g, int x1, int y1, int x2, int y2) {
+    UiCairoGraphics *gr = (UiCairoGraphics*)g;
+    cairo_set_line_width(gr->cr, 1);
+    cairo_move_to(gr->cr, (double)x1 + 0.5, (double)y1 + 0.5);
+    cairo_line_to(gr->cr, (double)x2 + 0.5, (double)y2 + 0.5);
+    cairo_stroke(gr->cr);
+}
+
+void ui_draw_rect(UiGraphics *g, int x, int y, int w, int h, int fill) {
+    UiCairoGraphics *gr = (UiCairoGraphics*)g;
+    cairo_set_line_width(gr->cr, 1);
+    cairo_rectangle(gr->cr, x + 0.5, y + 0.5 , w, h);
+    if(fill) {
+        cairo_fill(gr->cr);
+    } else {
+        cairo_stroke(gr->cr);
+    }
+}
+
+void ui_draw_text(UiGraphics *g, int x, int y, UiTextLayout *text) {
+    UiCairoGraphics *gr = (UiCairoGraphics*)g; 
+    cairo_move_to(gr->cr, x, y);
+    pango_cairo_show_layout(gr->cr, text->layout);
+}
+