diff options
Diffstat (limited to 'lib/wx/examples/demo/ex_canvas_paint.erl')
| -rw-r--r-- | lib/wx/examples/demo/ex_canvas_paint.erl | 16 |
1 files changed, 10 insertions, 6 deletions
diff --git a/lib/wx/examples/demo/ex_canvas_paint.erl b/lib/wx/examples/demo/ex_canvas_paint.erl index aa510f5342..75eb840b04 100644 --- a/lib/wx/examples/demo/ex_canvas_paint.erl +++ b/lib/wx/examples/demo/ex_canvas_paint.erl @@ -157,10 +157,15 @@ handle_event(#wx{event = #wxMouse{type = motion, x = X, y = Y}}, {noreply, State#state{old_pos = {X,Y}}}; %% Resize event handle_event(#wx{event = #wxSize{size = {W,H}}}, State = #state{bitmap=Prev}) -> - wxBitmap:destroy(Prev), - Bitmap = wxBitmap:new(W,H), - draw(State#state.canvas, Bitmap, fun(DC) -> wxDC:clear(DC) end), - {noreply, State#state{bitmap=Bitmap}}; + case W > 0 andalso H > 0 of + true -> + wxBitmap:destroy(Prev), + Bitmap = wxBitmap:new(W,H), + draw(State#state.canvas, Bitmap, fun(DC) -> wxDC:clear(DC) end), + {noreply, State#state{bitmap=Bitmap}}; + false -> + {noreply, State} + end; handle_event(#wx{event = #wxMouse{type = left_dclick,x = X,y = Y}}, State = #state{}) -> wxPanel:connect(State#state.canvas, motion), {noreply, State#state{old_pos = {X,Y}}}; @@ -235,11 +240,10 @@ draw(Canvas, Bitmap, Fun) -> CDC = wxClientDC:new(Canvas), Fun(MemoryDC), - wxDC:blit(CDC, {0,0}, {wxBitmap:getWidth(Bitmap), wxBitmap:getHeight(Bitmap)}, MemoryDC, {0,0}), - + wxClientDC:destroy(CDC), wxMemoryDC:destroy(MemoryDC). |