Windows: remove necessity to compile with -DFLTK_HIDPI_SUPPORT to make WIN32 FLTK apps DPI-aware.

At this point, Windows FLTK apps detect HighDPI displays and rescale their GUI accordingly. They also
all reply to ctrl/+/-/0/ keystrokes to enlarge/shrink/reset their windows. 

git-svn-id: file:///fltk/svn/fltk/branches/branch-1.4@12723 ea41ed52-d2ee-0310-a9c1-e6b18d33e121

FL/win32.H

@@ -55,9 +55,7 @@ extern FL_EXPORT struct Fl_XMap {
   COLORREF rgb;	// this should be the type the RGB() macro returns
   HPEN pen;	// pen, 0 if none created yet
   int brush;	// ref to solid brush, 0 if none created yet
-#ifdef FLTK_HIDPI_SUPPORT
   int pwidth;   // the width of the pen, if present
-#endif
 } *fl_current_xmap;
 inline COLORREF fl_RGB() {return fl_current_xmap->rgb;}
 inline HPEN fl_pen() {return fl_current_xmap->pen;}

src/Fl_win32.cxx

@@ -87,10 +87,8 @@ void fl_cleanup_dc_list(void);
 # include <wchar.h>
 #endif
 
-#ifdef FLTK_HIDPI_SUPPORT
+typedef HRESULT(WINAPI * SetProcessDpiAwareness_type)(int);
-  typedef HRESULT(WINAPI * SetProcessDpiAwareness_type)(int);
+static SetProcessDpiAwareness_type fl_SetProcessDpiAwareness = NULL;
-  static SetProcessDpiAwareness_type fl_SetProcessDpiAwareness = NULL;
-#endif
 
 extern bool fl_clipboard_notify_empty(void);
 extern void fl_trigger_clipboard_notify(int source);
@@ -522,7 +520,6 @@ void Fl_WinAPI_Screen_Driver::open_display_platform() {
     return;
 
   beenHereDoneThat = 1;
-#ifdef FLTK_HIDPI_SUPPORT
   HMODULE hMod = LoadLibrary("Shcore.DLL");
   if (hMod) {
     fl_SetProcessDpiAwareness = (SetProcessDpiAwareness_type)GetProcAddress(hMod, "SetProcessDpiAwareness");
@@ -533,14 +530,12 @@ void Fl_WinAPI_Screen_Driver::open_display_platform() {
       else fl_SetProcessDpiAwareness = NULL;
     }
   }
-#endif // FLTK_HIDPI_SUPPORT
   OleInitialize(0L);
 
   get_imm_module();
 }
 
 
-#ifdef FLTK_HIDPI_SUPPORT
 void Fl_WinAPI_Screen_Driver::init_screen_scale_factors() {
   typedef HRESULT(WINAPI * GetDpiForMonitor_type)(HMONITOR, int, UINT *, UINT *);
   HMODULE hMod = LoadLibrary("Shcore.DLL");
@@ -558,7 +553,6 @@ void Fl_WinAPI_Screen_Driver::init_screen_scale_factors() {
     }
   }
 }
-#endif // FLTK_HIDPI_SUPPORT
 
 
 class Fl_Win32_At_Exit {
@@ -852,16 +846,9 @@ void Fl_WinAPI_System_Driver::paste(Fl_Widget &receiver, int clipboard, const ch
 	int hdots = GetDeviceCaps(hdc, HORZRES);
 	ReleaseDC(NULL, hdc);
 	float factor = (100.f * hmm) / hdots;
-#ifdef FLTK_HIDPI_SUPPORT
 	float scaling = Fl::screen_driver()->scale(receiver.top_window()->driver()->screen_num());
 	width = int(width / (scaling * factor)); // convert to screen pixel unit
 	height = int(height / (scaling * factor));
-#else
-	float scaling = ((Fl_WinAPI_Screen_Driver *)Fl::screen_driver())->DWM_scaling_factor();
-	width = int(width * scaling / factor); // convert to screen pixel unit
-	height = int(height * scaling / factor);
-	scaling = 1;
-#endif
 	RECT rect = {0, 0, width, height};
 	Fl_Image_Surface *surf = new Fl_Image_Surface(width, height, 1);
 	Fl_Surface_Device::push_current(surf);
@@ -1180,7 +1167,6 @@ static LRESULT CALLBACK WndProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lPar
   if (window) {
     switch (uMsg) {
 
-#ifdef FLTK_HIDPI_SUPPORT
       case WM_DPICHANGED: { // 0x02E0
 	if (fl_SetProcessDpiAwareness && !Fl_WinAPI_Window_Driver::data_for_resize_window_between_screens_.busy) {
 	  RECT r;
@@ -1193,7 +1179,6 @@ static LRESULT CALLBACK WndProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lPar
 	}
 	return 0;
       }
-#endif // FLTK_HIDPI_SUPPORT
 
       case WM_QUIT: // this should not happen?
 	Fl::fatal("WM_QUIT message");
@@ -2703,18 +2688,13 @@ void Fl_WinAPI_Window_Driver::capture_titlebar_and_borders(Fl_Shared_Image *&top
   ww /= scaling;
   if (wsides <= 1)
     ww = w() + 2 * wsides;
-#ifdef FLTK_HIDPI_SUPPORT
-  float DWMscaling = scaling;
-#else
-  float DWMscaling = ((Fl_WinAPI_Screen_Driver *)Fl::screen_driver())->DWM_scaling_factor();
-#endif
   // capture the 4 window sides from screen
   Fl_WinAPI_Screen_Driver *dr = (Fl_WinAPI_Screen_Driver *)Fl::screen_driver();
   if (htop) {
     r_top = dr->read_win_rectangle_unscaled(r.left, r.top, r.right - r.left, htop);
     top = Fl_Shared_Image::get(r_top);
-    if (DWMscaling != 1)
+    if (scaling != 1)
-      top->scale(ww, htop / DWMscaling, 0, 1);
+      top->scale(ww, htop / scaling, 0, 1);
   }
   if (wsides) {
     r_left = dr->read_win_rectangle_unscaled(r.left, r.top + htop, wsides, h() * scaling);

src/drivers/GDI/Fl_GDI_Copy_Surface_Driver.cxx

@@ -60,12 +60,8 @@ Fl_GDI_Copy_Surface_Driver::Fl_GDI_Copy_Surface_Driver(int w, int h) : Fl_Copy_S
   float factorw = (100.f * hmm) / hdots;
   float factorh = (100.f * vmm) / vdots;
   // Global display scaling factor: 1, 1.25, 1.5, 1.75, etc...
-#ifdef FLTK_HIDPI_SUPPORT
   float scaling = Fl_Graphics_Driver::default_driver().scale();
   ((Fl_GDI_Graphics_Driver*)driver())->scale(scaling);
-#else
-  float scaling = 1/((Fl_WinAPI_Screen_Driver*)Fl::screen_driver())->DWM_scaling_factor();
-#endif
   RECT rect; rect.left = 0; rect.top = 0; rect.right = (LONG)((w*scaling) * factorw); rect.bottom = (LONG)((h*scaling) * factorh);
   gc = CreateEnhMetaFile (NULL, NULL, &rect, NULL);
   if (gc != NULL) {

src/drivers/GDI/Fl_GDI_Graphics_Driver_color.cxx

@@ -86,9 +86,7 @@ static void set_xmap(Fl_XMap& xmap, COLORREF c, int lw) {
 //  xmap.pen = CreatePen(PS_SOLID, 1, xmap.rgb);                        // get a pen into xmap.pen
   LOGBRUSH penbrush = {BS_SOLID, xmap.rgb, 0};
   xmap.pen = ExtCreatePen(PS_GEOMETRIC | PS_ENDCAP_FLAT | PS_JOIN_ROUND, lw, &penbrush, 0, 0);
-#ifdef FLTK_HIDPI_SUPPORT
   xmap.pwidth = lw;
-#endif
   xmap.brush = -1;
 }
 
@@ -100,11 +98,7 @@ void Fl_GDI_Graphics_Driver::color(Fl_Color i) {
     Fl_Graphics_Driver::color(i);
     Fl_XMap &xmap = fl_xmap[i];
     int tw = line_width_ ? line_width_ : int(scale_); if (!tw) tw = 1;
-    if (!xmap.pen
+    if (!xmap.pen || xmap.pwidth != tw) {
-#ifdef FLTK_HIDPI_SUPPORT
-        || xmap.pwidth != tw
-#endif
-        ) {
 #if USE_COLORMAP
       if (fl_palette) {
 	set_xmap(xmap, PALETTEINDEX(i), tw);
@@ -126,11 +120,7 @@ void Fl_GDI_Graphics_Driver::color(uchar r, uchar g, uchar b) {
   COLORREF c = RGB(r,g,b);
   Fl_Graphics_Driver::color( fl_rgb_color(r, g, b) );
   int tw = line_width_ ? line_width_ : int(scale_); if (!tw) tw = 1;
-  if (!xmap.pen || c != xmap.rgb
+  if (!xmap.pen || c != xmap.rgb || tw != xmap.pwidth) {
-#ifdef FLTK_HIDPI_SUPPORT
-      || tw != xmap.pwidth
-#endif
-      ) {
     clear_xmap(xmap);
     set_xmap(xmap, c, tw);
   }

src/drivers/WinAPI/Fl_WinAPI_Screen_Driver.H

@@ -42,9 +42,7 @@ protected:
   static BOOL CALLBACK screen_cb(HMONITOR mon, HDC, LPRECT r, LPARAM);
   BOOL screen_cb(HMONITOR mon, HDC, LPRECT r);
   int get_mouse_unscaled(int &mx, int &my);
-#ifdef FLTK_HIDPI_SUPPORT
   void init_screen_scale_factors();
-#endif
 
 public:
   Fl_WinAPI_Screen_Driver() : Fl_Screen_Driver() {
@@ -86,7 +84,6 @@ public:
   virtual void disable_im();
   virtual void open_display_platform();
   virtual void offscreen_size(Fl_Offscreen off, int &width, int &height);
-#if defined(FLTK_HIDPI_SUPPORT)  
   virtual APP_SCALING_CAPABILITY rescalable() {
     return PER_SCREEN_APP_SCALING;
   }
@@ -96,9 +93,6 @@ public:
   virtual void scale(int n, float f) {
     scale_of_screen[n] = f;
   }
-#else
-  float DWM_scaling_factor();
-#endif
   virtual float desktop_scale_factor();
 };
 

src/drivers/WinAPI/Fl_WinAPI_Screen_Driver.cxx

@@ -600,32 +600,6 @@ Fl_RGB_Image *Fl_WinAPI_Screen_Driver::read_win_rectangle_unscaled(int X, int Y,
   return rgb;
 }
 
-#ifndef FLTK_HIDPI_SUPPORT
-/* Returns the current desktop scaling factor for screen_num (1.75 for example)
- */
-float Fl_WinAPI_Screen_Driver::DWM_scaling_factor() {
-  // Compute the global desktop scaling factor: 1, 1.25, 1.5, 1.75, etc...
-  // This factor can be set in Windows 10 by
-  // "Change the size of text, apps and other items" in display settings.
-  // We don't cache this value because it can change while the app is running.
-  HDC hdc = GetDC(NULL);
-  int hr = GetDeviceCaps(hdc, HORZRES); // pixels visible to the app
-#ifndef DESKTOPHORZRES
-#define DESKTOPHORZRES 118
-  /* As of 27 august 2016, the DESKTOPHORZRES flag for GetDeviceCaps()
-   has disappeared from Microsoft online doc, but is quoted in numerous coding examples
-   e.g., https://social.msdn.microsoft.com/Forums/en-US/6acc3b21-23a4-4a00-90b4-968a43e1ccc8/capture-screen-with-high-dpi?forum=vbgeneral
-   It is necessary for the computation of the scaling factor at runtime as done here.
-   */
-#endif
-  int dhr = GetDeviceCaps(hdc, DESKTOPHORZRES); // true number of pixels on display
-  ReleaseDC(NULL, hdc);
-  float scaling = dhr/float(hr);
-  scaling = int(scaling * 100 + 0.5)/100.; // round to 2 digits after decimal point
-  return scaling;
-}
-
-#endif // ! FLTK_HIDPI_SUPPORT
 
 void Fl_WinAPI_Screen_Driver::offscreen_size(Fl_Offscreen off, int &width, int &height)
 {

src/drivers/WinAPI/Fl_WinAPI_Window_Driver.cxx

@@ -103,16 +103,10 @@ RECT // frame of the decorated window in screen coordinates
       GetWindowRect(fl_xid(win), &r);
     }
     int width, height;
-#ifdef FLTK_HIDPI_SUPPORT
     RECT  rc;
     GetClientRect(fl_xid(win), &rc);
     width = rc.right;
     height = rc.bottom;
-#else
-    float scaling = ((Fl_WinAPI_Screen_Driver*)Fl::screen_driver())->DWM_scaling_factor();
-    width = int(win->w() * scaling);
-    height = int(win->h() * scaling);
-#endif
     bx = (r.right - r.left - width)/2;
     if (bx < 1) bx = 1;
     by = bx;
@@ -137,14 +131,9 @@ int Fl_WinAPI_Window_Driver::decorated_h()
 {
   int bt, bx, by;
   border_width_title_bar_height(bx, by, bt);
-#ifdef FLTK_HIDPI_SUPPORT
   float s = Fl::screen_driver()->scale(screen_num());
   int mini_by = by/s; if (mini_by < 1) mini_by = 1;
   return h() + (bt + by)/s + mini_by;
-#else
-  float scaling = ((Fl_WinAPI_Screen_Driver*)Fl::screen_driver())->DWM_scaling_factor();
-  return h() + bt/scaling + 2 * by +1;
-#endif
 }
 
 

src/fl_dnd_win32.cxx

@@ -84,19 +84,6 @@ public:
     if( !pDataObj ) return E_INVALIDARG;
     // set e_modifiers here from grfKeyState, set e_x and e_root_x
     // check if FLTK handles this drag and return if it can't (i.e. BMP drag without filename)
-/* Tricky point here: Not DPI–aware applications use different units for the 'POINTL pt' argument
-of the DragEnter, DragOver, and Drop member functions.
-DragEnter receives the mouse coordinates in unscaled screen units,
-whereas DragOver and Drop receive the mouse coordinates in scaled units.
- 
-DPI–aware applications transmit unscaled screen units to all 3 member functions.
-These coordinates should be divided by the window's scale to get FLTK units.
-*/
-#ifndef FLTK_HIDPI_SUPPORT
-    POINT mp;
-    GetCursorPos(&mp); // bypass Windows bug that gives mouse coordinates in unscaled screen units
-    pt.x = mp.x; pt.y = mp.y;
-#endif
     POINT ppt;
     Fl::e_x_root = ppt.x = pt.x;
     Fl::e_y_root = ppt.y = pt.y;