text widget has a constant buffer and owns the string to draw now

(passing a const char * from a local stack context is not really a
good idea!)
added more efficiet draw method for characters in vga driver
protected desktop for now against too often redraws (boolean global
variable needs_redraw, this is later a soffisticated set-of-areas-to
-redraw algorithm)

1 files changed, 17 insertions, 0 deletions

diff --git a/src/gui/desktop.c b/src/gui/desktop.c
index 6592b52..ad4aad9 100644
--- a/src/gui/desktop.c
+++ b/src/gui/desktop.c
@@ -28,6 +28,7 @@ void desktop_init( desktop_t *desktop, const int w, const int h, const vga_color
 
 	desktop->mouse_x = w / 2;
 	desktop->mouse_y = h / 2;
+	desktop->needs_redrawing = true;
 
 	desktop->base.base.vtable = (widget_vtable_t *)&desktop_vtable;
 	desktop->base.vtable = (composite_widget_vtable_t *)&desktop_vtable;
@@ -38,6 +39,10 @@ void desktop_draw( void *obj, graphics_context_t *context )
 {
 	desktop_t *desktop = obj;
 
+	if( !desktop->needs_redrawing ) {
+		return;
+	}
+
 	vga_clear_screen( context, desktop->base.base.background_color );
 
 	composite_widget_draw( obj, context );
@@ -56,16 +61,26 @@ void desktop_draw( void *obj, graphics_context_t *context )
 			vga_set_pixel( context, desktop->mouse_x, desktop->mouse_y + i, VGA_COLOR_WHITE );
 		}
 	}
+
+	desktop->needs_redrawing = false;
 }
 
 void desktop_on_mouse_down( void *obj, const int x, const int y )
 {
+	desktop_t *desktop = obj;
+
 	composite_widget_on_mouse_down( obj, x, y );
+
+	desktop->needs_redrawing = true;
 }
 
 void desktop_on_mouse_up( void *obj, const int x, const int y )
 {
+	desktop_t *desktop = obj;
+
 	composite_widget_on_mouse_up( obj, x, y );
+
+	desktop->needs_redrawing = true;
 }
 
 void desktop_on_mouse_move( void *obj, const int old_x, const int old_y, const int x, const int y )
@@ -76,4 +91,6 @@ void desktop_on_mouse_move( void *obj, const int old_x, const int old_y, const i
 	desktop->mouse_y = y;
 
 	composite_widget_on_mouse_move( obj, old_x, old_y, x, y );
+
+	desktop->needs_redrawing = true;
 }