Redraw window immediately on "live resizing"

examples/helloworld.cpp

@@ -1,5 +1,5 @@
 // LAF Library
-// Copyright (c) 2019-2020  Igara Studio S.A.
+// Copyright (c) 2019-2021  Igara Studio S.A.
 //
 // This file is released under the terms of the MIT license.
 // Read LICENSE.txt for more information.
@@ -39,6 +39,7 @@ int app_main(int argc, char* argv[])
 
   display->setNativeMouseCursor(os::kArrowCursor);
   display->setTitle("Hello World");
+  display->handleResize = draw_display;
 
   // On macOS: With finishLaunching() we start processing
   // NSApplicationDelegate events. After calling this we'll start
@@ -92,6 +93,12 @@ int app_main(int argc, char* argv[])
             display->setScale(1 + (int)(ev.scancode() - os::kKey1));
             redraw = true;
             break;
+
+          case os::kKeyF:
+          case os::kKeyF11:
+            display->setFullscreen(!display->isFullscreen());
+            break;
+
           default:
             // Do nothing
             break;

os/CMakeLists.txt

@@ -59,7 +59,6 @@ if(LAF_BACKEND STREQUAL "skia")
   endif()
   list(APPEND LAF_OS_SOURCES
     skia/os.cpp
-    skia/resize_surface.cpp
     skia/skia_color_space.cpp
     skia/skia_display.cpp
     skia/skia_draw_text.cpp

os/display.h

@@ -1,5 +1,5 @@
 // LAF OS Library
-// Copyright (c) 2018-2020  Igara Studio S.A.
+// Copyright (c) 2018-2021  Igara Studio S.A.
 // Copyright (c) 2012-2018  David Capello
 //
 // This file is released under the terms of the MIT license.
@@ -15,6 +15,7 @@
 #include "os/ref.h"
 #include "os/surface_list.h"
 
+#include <functional>
 #include <string>
 
 namespace os {
@@ -30,6 +31,14 @@ namespace os {
 
     virtual ~Display() { }
 
+    // Function called to handle a "live resize"/resizing loop. If
+    // this is nullptr, an Event::ResizeDisplay is generated when the
+    // resizing is finished.
+    //
+    // TODO I think we should have a DisplayDelegate for this instead
+    //      of a public property.
+    std::function<void(os::Display*)> handleResize = nullptr;
+
     // Returns the real and current display's size (without scale applied).
     virtual int width() const = 0;
     virtual int height() const = 0;

os/osx/window.h

@@ -1,5 +1,5 @@
 // LAF OS Library
-// Copyright (C) 2018-2020  Igara Studio S.A.
+// Copyright (C) 2018-2021  Igara Studio S.A.
 // Copyright (C) 2012-2017  David Capello
 //
 // This file is released under the terms of the MIT license.
@@ -36,6 +36,7 @@ class OSXWindowImpl {
   virtual void onDrawRect(const gfx::Rect& rect) = 0;
   virtual void onWindowChanged() = 0;
   virtual void onStartResizing() = 0;
+  virtual void onResizing(gfx::Size& size) = 0;
   virtual void onEndResizing() = 0;
 
   // This generally happens when the window is moved to another

os/osx/window.mm

@@ -1,5 +1,5 @@
 // LAF OS Library
-// Copyright (C) 2020  Igara Studio S.A.
+// Copyright (C) 2019-2020  Igara Studio S.A.
 // Copyright (C) 2012-2017  David Capello
 //
 // This file is released under the terms of the MIT license.
@@ -51,6 +51,10 @@ - (OSXWindow*)initWithImpl:(OSXWindowImpl*)impl
   OSXView* view = [[OSXView alloc] initWithFrame:rect];
   [view setAutoresizingMask:NSViewWidthSizable | NSViewHeightSizable];
 
+  // Redraw the entire window content when we resize it.
+  // TODO add support to avoid redrawing the entire window
+  self.preservesContentDuringLiveResize = false;
+
   [self setDelegate:m_delegate];
   [self setContentView:view];
   [self center];

os/osx/window_delegate.h

@@ -1,5 +1,5 @@
 // LAF OS Library
-// Copyright (C) 2020  Igara Studio S.A.
+// Copyright (C) 2020-2021  Igara Studio S.A.
 // Copyright (C) 2015  David Capello
 //
 // This file is released under the terms of the MIT license.
@@ -41,6 +41,15 @@ class OSXWindowImpl;
   m_impl->onStartResizing();
 }
 
+- (NSSize)windowWillResize:(NSWindow*)sender
+                    toSize:(NSSize)frameSize
+{
+  NSView* view = sender.contentView;
+  gfx::Size sz(view.bounds.size.width, view.bounds.size.height);
+  m_impl->onResizing(sz);
+  return frameSize;
+}
+
 - (void)windowDidEndLiveResize:(NSNotification*)notification
 {
   m_impl->onEndResizing();

os/skia/skia_display.cpp

@@ -1,5 +1,5 @@
 // LAF OS Library
-// Copyright (c) 2018-2020  Igara Studio S.A.
+// Copyright (C) 2018-2021  Igara Studio S.A.
 // Copyright (C) 2012-2018  David Capello
 //
 // This file is released under the terms of the MIT license.
@@ -46,16 +46,18 @@ void SkiaDisplay::resetSkiaSurface()
     m_surface = nullptr;
 
   m_customSurface = false;
-  resize(m_window.clientSize());
+  resizeSkiaSurface(m_window.clientSize());
 }
 
-void SkiaDisplay::resize(const gfx::Size& size)
+void SkiaDisplay::resizeSkiaSurface(const gfx::Size& size)
 {
   if (!m_initialized || m_customSurface)
     return;
 
   gfx::Size newSize(size.w / m_window.scale(),
                     size.h / m_window.scale());
+  newSize.w = std::max(1, newSize.w);
+  newSize.h = std::max(1, newSize.h);
 
   if (m_initialized &&
       m_surface &&
@@ -138,19 +140,6 @@ void SkiaDisplay::setFullscreen(bool state)
   m_window.setFullscreen(state);
 }
 
-void SkiaDisplay::resetSurfaceAndQueueResizeDisplayEvent()
-{
-  // Redraw the full skia surface
-  if (m_surface)
-    resetSkiaSurface();
-
-  // Generate the resizing display event to redraw everything.
-  Event ev;
-  ev.setType(Event::ResizeDisplay);
-  ev.setDisplay(this);
-  os::queue_event(ev);
-}
-
 void SkiaDisplay::setTitle(const std::string& title)
 {
   m_window.setTitle(title);

os/skia/skia_display.h

@@ -25,6 +25,7 @@ class SkiaDisplay : public Display {
   bool isInitialized() const { return m_initialized; }
   void setSkiaSurface(SkiaSurface* surface);
   void resetSkiaSurface();
+  void resizeSkiaSurface(const gfx::Size& size);
 
   void resize(const gfx::Size& size);
 
@@ -74,8 +75,6 @@ class SkiaDisplay : public Display {
   void setColorSpace(const os::ColorSpaceRef& colorSpace);
   os::ColorSpaceRef currentMonitorColorSpace() const;
 
-  void resetSurfaceAndQueueResizeDisplayEvent();
-
   void onTabletAPIChange();
 
   // Returns the HWND on Windows.