Use QScreen for Desktop::{size,workspace}

Qt 5.0 adds the QScreen API, which exposes enough information that
Desktop::{size,workspace} no longer needs to fall back to Win32/Xlib. I
manually tested that this seems to give the same exact answers as the
Xlib path (though it technically goes a different route for
Desktop::size.)

Author: jchv

hiro/qt/desktop.cpp

@@ -3,57 +3,19 @@
 namespace hiro {
 
 auto pDesktop::size() -> Size {
-  #if defined(DISPLAY_WINDOWS)
-  return {GetSystemMetrics(SM_CXVIRTUALSCREEN), GetSystemMetrics(SM_CYVIRTUALSCREEN)};
-  #elif defined(DISPLAY_XORG)
-  auto display = XOpenDisplay(nullptr);
-  int screen = DefaultScreen(display);
-  XWindowAttributes attributes;
-  XGetWindowAttributes(display, RootWindow(display, screen), &attributes);
-  XCloseDisplay(display);
-  return {attributes.width, attributes.height};
-  #else
-  //this only returns the geometry of the primary monitor rather than the entire desktop
-  QRect rect = QApplication::desktop()->screenGeometry();
+  QRect rect;
+  for(QScreen* screen : QApplication::screens()) {
+    rect = rect.united(screen->geometry());
+  }
   return {rect.width(), rect.height()};
-  #endif
 }
 
 auto pDesktop::workspace() -> Geometry {
-  #if defined(DISPLAY_WINDOWS)
-  RECT rc;
-  SystemParametersInfo(SPI_GETWORKAREA, 0, &rc, 0);
-  return {rc.left, rc.top, rc.right - rc.left, rc.bottom - rc.top};
-  #elif defined(DISPLAY_XORG)
-  auto display = XOpenDisplay(nullptr);
-  int screen = DefaultScreen(display);
-
-  int format;
-  unsigned char* data = nullptr;
-  unsigned long items, after;
-  XlibAtom returnAtom;
-
-  XlibAtom netWorkarea = XInternAtom(display, "_NET_WORKAREA", XlibTrue);
-  int result = XGetWindowProperty(
-    display, RootWindow(display, screen), netWorkarea, 0, 4, XlibFalse,
-    XInternAtom(display, "CARDINAL", XlibTrue), &returnAtom, &format, &items, &after, &data
-  );
-
-  XlibAtom cardinal = XInternAtom(display, "CARDINAL", XlibTrue);
-  if(result == Success && returnAtom == cardinal && format == 32 && items == 4) {
-    unsigned long* workarea = (unsigned long*)data;
-    XCloseDisplay(display);
-    return {(int)workarea[0], (int)workarea[1], (int)workarea[2], (int)workarea[3]};
+  QRect rect;
+  for(QScreen* screen : QApplication::screens()) {
+    rect = rect.united(screen->geometry());
   }
-
-  XCloseDisplay(display);
-  auto size = Desktop::size();
-  return {0, 0, size.width(), size.height()};
-  #else
-  //this only returns the workspace of the primary monitor rather than the entire desktop
-  QRect rect = QApplication::desktop()->availableGeometry();
   return {rect.x(), rect.y(), rect.width(), rect.height()};
-  #endif
 }
 
 }