SDL  2.0
SDL_windowsmessagebox.c
Go to the documentation of this file.
1 /*
2  Simple DirectMedia Layer
3  Copyright (C) 1997-2018 Sam Lantinga <slouken@libsdl.org>
4 
5  This software is provided 'as-is', without any express or implied
6  warranty. In no event will the authors be held liable for any damages
7  arising from the use of this software.
8 
9  Permission is granted to anyone to use this software for any purpose,
10  including commercial applications, and to alter it and redistribute it
11  freely, subject to the following restrictions:
12 
13  1. The origin of this software must not be misrepresented; you must not
14  claim that you wrote the original software. If you use this software
15  in a product, an acknowledgment in the product documentation would be
16  appreciated but is not required.
17  2. Altered source versions must be plainly marked as such, and must not be
18  misrepresented as being the original software.
19  3. This notice may not be removed or altered from any source distribution.
20 */
21 #include "../../SDL_internal.h"
22 
23 #if SDL_VIDEO_DRIVER_WINDOWS
24 
25 #include "../../core/windows/SDL_windows.h"
26 
27 #include "SDL_assert.h"
28 #include "SDL_windowsvideo.h"
29 
30 
31 #ifndef SS_EDITCONTROL
32 #define SS_EDITCONTROL 0x2000
33 #endif
34 
35 /* Display a Windows message box */
36 
37 #pragma pack(push, 1)
38 
39 typedef struct
40 {
41  WORD dlgVer;
42  WORD signature;
43  DWORD helpID;
44  DWORD exStyle;
45  DWORD style;
46  WORD cDlgItems;
47  short x;
48  short y;
49  short cx;
50  short cy;
51 } DLGTEMPLATEEX;
52 
53 typedef struct
54 {
55  DWORD helpID;
56  DWORD exStyle;
57  DWORD style;
58  short x;
59  short y;
60  short cx;
61  short cy;
62  DWORD id;
63 } DLGITEMTEMPLATEEX;
64 
65 #pragma pack(pop)
66 
67 typedef struct
68 {
69  DLGTEMPLATEEX* lpDialog;
70  Uint8 *data;
71  size_t size;
72  size_t used;
73 } WIN_DialogData;
74 
75 
76 static INT_PTR MessageBoxDialogProc(HWND hDlg, UINT iMessage, WPARAM wParam, LPARAM lParam)
77 {
78  switch ( iMessage ) {
79  case WM_COMMAND:
80  /* Return the ID of the button that was pushed */
81  EndDialog(hDlg, LOWORD(wParam));
82  return TRUE;
83 
84  default:
85  break;
86  }
87  return FALSE;
88 }
89 
90 static SDL_bool ExpandDialogSpace(WIN_DialogData *dialog, size_t space)
91 {
92  size_t size = dialog->size;
93 
94  if (size == 0) {
95  size = space;
96  } else {
97  while ((dialog->used + space) > size) {
98  size *= 2;
99  }
100  }
101  if (size > dialog->size) {
102  void *data = SDL_realloc(dialog->data, size);
103  if (!data) {
104  SDL_OutOfMemory();
105  return SDL_FALSE;
106  }
107  dialog->data = data;
108  dialog->size = size;
109  dialog->lpDialog = (DLGTEMPLATEEX*)dialog->data;
110  }
111  return SDL_TRUE;
112 }
113 
114 static SDL_bool AlignDialogData(WIN_DialogData *dialog, size_t size)
115 {
116  size_t padding = (dialog->used % size);
117 
118  if (!ExpandDialogSpace(dialog, padding)) {
119  return SDL_FALSE;
120  }
121 
122  dialog->used += padding;
123 
124  return SDL_TRUE;
125 }
126 
127 static SDL_bool AddDialogData(WIN_DialogData *dialog, const void *data, size_t size)
128 {
129  if (!ExpandDialogSpace(dialog, size)) {
130  return SDL_FALSE;
131  }
132 
133  SDL_memcpy(dialog->data+dialog->used, data, size);
134  dialog->used += size;
135 
136  return SDL_TRUE;
137 }
138 
139 static SDL_bool AddDialogString(WIN_DialogData *dialog, const char *string)
140 {
141  WCHAR *wstring;
142  WCHAR *p;
143  size_t count;
144  SDL_bool status;
145 
146  if (!string) {
147  string = "";
148  }
149 
150  wstring = WIN_UTF8ToString(string);
151  if (!wstring) {
152  return SDL_FALSE;
153  }
154 
155  /* Find out how many characters we have, including null terminator */
156  count = 0;
157  for (p = wstring; *p; ++p) {
158  ++count;
159  }
160  ++count;
161 
162  status = AddDialogData(dialog, wstring, count*sizeof(WCHAR));
163  SDL_free(wstring);
164  return status;
165 }
166 
167 static int s_BaseUnitsX;
168 static int s_BaseUnitsY;
169 static void Vec2ToDLU(short *x, short *y)
170 {
171  SDL_assert(s_BaseUnitsX != 0); /* we init in WIN_ShowMessageBox(), which is the only public function... */
172 
173  *x = MulDiv(*x, 4, s_BaseUnitsX);
174  *y = MulDiv(*y, 8, s_BaseUnitsY);
175 }
176 
177 
178 static SDL_bool AddDialogControl(WIN_DialogData *dialog, WORD type, DWORD style, DWORD exStyle, int x, int y, int w, int h, int id, const char *caption)
179 {
180  DLGITEMTEMPLATEEX item;
181  WORD marker = 0xFFFF;
182  WORD extraData = 0;
183 
184  SDL_zero(item);
185  item.style = style;
186  item.exStyle = exStyle;
187  item.x = x;
188  item.y = y;
189  item.cx = w;
190  item.cy = h;
191  item.id = id;
192 
193  Vec2ToDLU(&item.x, &item.y);
194  Vec2ToDLU(&item.cx, &item.cy);
195 
196  if (!AlignDialogData(dialog, sizeof(DWORD))) {
197  return SDL_FALSE;
198  }
199  if (!AddDialogData(dialog, &item, sizeof(item))) {
200  return SDL_FALSE;
201  }
202  if (!AddDialogData(dialog, &marker, sizeof(marker))) {
203  return SDL_FALSE;
204  }
205  if (!AddDialogData(dialog, &type, sizeof(type))) {
206  return SDL_FALSE;
207  }
208  if (!AddDialogString(dialog, caption)) {
209  return SDL_FALSE;
210  }
211  if (!AddDialogData(dialog, &extraData, sizeof(extraData))) {
212  return SDL_FALSE;
213  }
214  ++dialog->lpDialog->cDlgItems;
215 
216  return SDL_TRUE;
217 }
218 
219 static SDL_bool AddDialogStatic(WIN_DialogData *dialog, int x, int y, int w, int h, const char *text)
220 {
221  DWORD style = WS_VISIBLE | WS_CHILD | SS_LEFT | SS_NOPREFIX | SS_EDITCONTROL;
222  return AddDialogControl(dialog, 0x0082, style, 0, x, y, w, h, -1, text);
223 }
224 
225 static SDL_bool AddDialogButton(WIN_DialogData *dialog, int x, int y, int w, int h, const char *text, int id, SDL_bool isDefault)
226 {
227  DWORD style = WS_VISIBLE | WS_CHILD;
228  if (isDefault) {
229  style |= BS_DEFPUSHBUTTON;
230  } else {
231  style |= BS_PUSHBUTTON;
232  }
233  return AddDialogControl(dialog, 0x0080, style, 0, x, y, w, h, id, text);
234 }
235 
236 static void FreeDialogData(WIN_DialogData *dialog)
237 {
238  SDL_free(dialog->data);
239  SDL_free(dialog);
240 }
241 
242 static WIN_DialogData *CreateDialogData(int w, int h, const char *caption)
243 {
244  WIN_DialogData *dialog;
245  DLGTEMPLATEEX dialogTemplate;
246  WORD WordToPass;
247 
248  SDL_zero(dialogTemplate);
249  dialogTemplate.dlgVer = 1;
250  dialogTemplate.signature = 0xffff;
251  dialogTemplate.style = (WS_CAPTION | DS_CENTER | DS_SHELLFONT);
252  dialogTemplate.x = 0;
253  dialogTemplate.y = 0;
254  dialogTemplate.cx = w;
255  dialogTemplate.cy = h;
256  Vec2ToDLU(&dialogTemplate.cx, &dialogTemplate.cy);
257 
258  dialog = (WIN_DialogData *)SDL_calloc(1, sizeof(*dialog));
259  if (!dialog) {
260  return NULL;
261  }
262 
263  if (!AddDialogData(dialog, &dialogTemplate, sizeof(dialogTemplate))) {
264  FreeDialogData(dialog);
265  return NULL;
266  }
267 
268  /* No menu */
269  WordToPass = 0;
270  if (!AddDialogData(dialog, &WordToPass, 2)) {
271  FreeDialogData(dialog);
272  return NULL;
273  }
274 
275  /* No custom class */
276  if (!AddDialogData(dialog, &WordToPass, 2)) {
277  FreeDialogData(dialog);
278  return NULL;
279  }
280 
281  /* title */
282  if (!AddDialogString(dialog, caption)) {
283  FreeDialogData(dialog);
284  return NULL;
285  }
286 
287  /* Font stuff */
288  {
289  /*
290  * We want to use the system messagebox font.
291  */
292  BYTE ToPass;
293 
294  NONCLIENTMETRICSA NCM;
295  NCM.cbSize = sizeof(NCM);
296  SystemParametersInfoA(SPI_GETNONCLIENTMETRICS, 0, &NCM, 0);
297 
298  /* Font size - convert to logical font size for dialog parameter. */
299  {
300  HDC ScreenDC = GetDC(NULL);
301  int LogicalPixelsY = GetDeviceCaps(ScreenDC, LOGPIXELSY);
302  if (!LogicalPixelsY) /* This can happen if the application runs out of GDI handles */
303  LogicalPixelsY = 72;
304  WordToPass = (WORD)(-72 * NCM.lfMessageFont.lfHeight / LogicalPixelsY);
305  ReleaseDC(NULL, ScreenDC);
306  }
307 
308  if (!AddDialogData(dialog, &WordToPass, 2)) {
309  FreeDialogData(dialog);
310  return NULL;
311  }
312 
313  /* Font weight */
314  WordToPass = (WORD)NCM.lfMessageFont.lfWeight;
315  if (!AddDialogData(dialog, &WordToPass, 2)) {
316  FreeDialogData(dialog);
317  return NULL;
318  }
319 
320  /* italic? */
321  ToPass = NCM.lfMessageFont.lfItalic;
322  if (!AddDialogData(dialog, &ToPass, 1)) {
323  FreeDialogData(dialog);
324  return NULL;
325  }
326 
327  /* charset? */
328  ToPass = NCM.lfMessageFont.lfCharSet;
329  if (!AddDialogData(dialog, &ToPass, 1)) {
330  FreeDialogData(dialog);
331  return NULL;
332  }
333 
334  /* font typeface. */
335  if (!AddDialogString(dialog, NCM.lfMessageFont.lfFaceName)) {
336  FreeDialogData(dialog);
337  return NULL;
338  }
339  }
340 
341  return dialog;
342 }
343 
344 int
345 WIN_ShowMessageBox(const SDL_MessageBoxData *messageboxdata, int *buttonid)
346 {
347  WIN_DialogData *dialog;
348  int i, x, y;
349  const SDL_MessageBoxButtonData *buttons = messageboxdata->buttons;
350  HFONT DialogFont;
351  SIZE Size;
352  RECT TextSize;
353  wchar_t* wmessage;
354  TEXTMETRIC TM;
355 
356  HWND ParentWindow = NULL;
357 
358  const int ButtonWidth = 88;
359  const int ButtonHeight = 26;
360  const int TextMargin = 16;
361  const int ButtonMargin = 12;
362 
363 
364  /* Jan 25th, 2013 - dant@fleetsa.com
365  *
366  *
367  * I've tried to make this more reasonable, but I've run in to a lot
368  * of nonsense.
369  *
370  * The original issue is the code was written in pixels and not
371  * dialog units (DLUs). All DialogBox functions use DLUs, which
372  * vary based on the selected font (yay).
373  *
374  * According to MSDN, the most reliable way to convert is via
375  * MapDialogUnits, which requires an HWND, which we don't have
376  * at time of template creation.
377  *
378  * We do however have:
379  * The system font (DLU width 8 for me)
380  * The font we select for the dialog (DLU width 6 for me)
381  *
382  * Based on experimentation, *neither* of these return the value
383  * actually used. Stepping in to MapDialogUnits(), the conversion
384  * is fairly clear, and uses 7 for me.
385  *
386  * As a result, some of this is hacky to ensure the sizing is
387  * somewhat correct.
388  *
389  * Honestly, a long term solution is to use CreateWindow, not CreateDialog.
390  *
391 
392  *
393  * In order to get text dimensions we need to have a DC with the desired font.
394  * I'm assuming a dialog box in SDL is rare enough we can to the create.
395  */
396  HDC FontDC = CreateCompatibleDC(0);
397 
398  {
399  /* Create a duplicate of the font used in system message boxes. */
400  LOGFONT lf;
401  NONCLIENTMETRICS NCM;
402  NCM.cbSize = sizeof(NCM);
403  SystemParametersInfo(SPI_GETNONCLIENTMETRICS, 0, &NCM, 0);
404  lf = NCM.lfMessageFont;
405  DialogFont = CreateFontIndirect(&lf);
406  }
407 
408  /* Select the font in to our DC */
409  SelectObject(FontDC, DialogFont);
410 
411  {
412  /* Get the metrics to try and figure our DLU conversion. */
413  GetTextMetrics(FontDC, &TM);
414 
415  /* Calculation from the following documentation:
416  * https://support.microsoft.com/en-gb/help/125681/how-to-calculate-dialog-base-units-with-non-system-based-font
417  * This fixes bug 2137, dialog box calculation with a fixed-width system font
418  */
419  {
420  SIZE extent;
421  GetTextExtentPoint32A(FontDC, "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz", 52, &extent);
422  s_BaseUnitsX = (extent.cx / 26 + 1) / 2;
423  }
424  /*s_BaseUnitsX = TM.tmAveCharWidth + 1;*/
425  s_BaseUnitsY = TM.tmHeight;
426  }
427 
428  /* Measure the *pixel* size of the string. */
429  wmessage = WIN_UTF8ToString(messageboxdata->message);
430  SDL_zero(TextSize);
431  DrawText(FontDC, wmessage, -1, &TextSize, DT_CALCRECT);
432 
433  /* Add some padding for hangs, etc. */
434  TextSize.right += 2;
435  TextSize.bottom += 2;
436 
437  /* Done with the DC, and the string */
438  DeleteDC(FontDC);
439  SDL_free(wmessage);
440 
441  /* Increase the size of the dialog by some border spacing around the text. */
442  Size.cx = TextSize.right - TextSize.left;
443  Size.cy = TextSize.bottom - TextSize.top;
444  Size.cx += TextMargin * 2;
445  Size.cy += TextMargin * 2;
446 
447  /* Ensure the size is wide enough for all of the buttons. */
448  if (Size.cx < messageboxdata->numbuttons * (ButtonWidth + ButtonMargin) + ButtonMargin)
449  Size.cx = messageboxdata->numbuttons * (ButtonWidth + ButtonMargin) + ButtonMargin;
450 
451  /* Add vertical space for the buttons and border. */
452  Size.cy += ButtonHeight + TextMargin;
453 
454  dialog = CreateDialogData(Size.cx, Size.cy, messageboxdata->title);
455  if (!dialog) {
456  return -1;
457  }
458 
459  if (!AddDialogStatic(dialog, TextMargin, TextMargin, TextSize.right - TextSize.left, TextSize.bottom - TextSize.top, messageboxdata->message)) {
460  FreeDialogData(dialog);
461  return -1;
462  }
463 
464  /* Align the buttons to the right/bottom. */
465  x = Size.cx - (ButtonWidth + ButtonMargin) * messageboxdata->numbuttons;
466  y = Size.cy - ButtonHeight - ButtonMargin;
467  for (i = messageboxdata->numbuttons - 1; i >= 0; --i) {
468  SDL_bool isDefault;
469 
471  isDefault = SDL_TRUE;
472  } else {
473  isDefault = SDL_FALSE;
474  }
475  if (!AddDialogButton(dialog, x, y, ButtonWidth, ButtonHeight, buttons[i].text, buttons[i].buttonid, isDefault)) {
476  FreeDialogData(dialog);
477  return -1;
478  }
479  x += ButtonWidth + ButtonMargin;
480  }
481 
482  /* If we have a parent window, get the Instance and HWND for them
483  * so that our little dialog gets exclusive focus at all times. */
484  if (messageboxdata->window) {
485  ParentWindow = ((SDL_WindowData*)messageboxdata->window->driverdata)->hwnd;
486  }
487 
488  *buttonid = (int)DialogBoxIndirect(NULL, (DLGTEMPLATE*)dialog->lpDialog, ParentWindow, (DLGPROC)MessageBoxDialogProc);
489 
490  FreeDialogData(dialog);
491  return 0;
492 }
493 
494 #endif /* SDL_VIDEO_DRIVER_WINDOWS */
495 
496 /* vi: set ts=4 sw=4 expandtab: */
const char * message
GLuint id
#define WIN_UTF8ToString(S)
Definition: SDL_windows.h:47
const char * title
SDL_Window * window
GLint GLint GLint GLint GLint x
Definition: SDL_opengl.h:1574
GLuint GLuint GLsizei count
Definition: SDL_opengl.h:1571
GLfloat GLfloat GLfloat GLfloat h
GLfloat GLfloat p
GLint GLenum GLsizei GLsizei GLsizei GLint GLsizei const GLvoid * data
Definition: SDL_opengl.h:1974
#define SDL_realloc
Individual button data.
#define SDL_memcpy
uint8_t Uint8
Definition: SDL_stdinc.h:157
#define SDL_free
#define TRUE
Definition: edid-parse.c:33
GLubyte GLubyte GLubyte GLubyte w
#define SDL_zero(x)
Definition: SDL_stdinc.h:416
GLint GLint GLint GLint GLint GLint y
Definition: SDL_opengl.h:1574
const SDL_MessageBoxButtonData * buttons
MessageBox structure containing title, text, window, etc.
GLsizeiptr size
return Display return Display Bool Bool int int int return Display XEvent Bool(*) XPointer return Display return Display Drawable _Xconst char unsigned int unsigned int return Display Pixmap Pixmap XColor XColor unsigned int unsigned int return Display _Xconst char char int char return Display Visual unsigned int int int char unsigned int unsigned int in i)
Definition: SDL_x11sym.h:50
#define SDL_assert(condition)
Definition: SDL_assert.h:169
#define NULL
Definition: begin_code.h:164
#define SDL_OutOfMemory()
Definition: SDL_error.h:52
SDL_bool
Definition: SDL_stdinc.h:139
GLbitfield flags
static char text[MAX_TEXT_LENGTH]
Definition: testime.c:47
#define SDL_calloc
GLuint GLuint GLsizei GLenum type
Definition: SDL_opengl.h:1571
void * driverdata
Definition: SDL_sysvideo.h:111
#define FALSE
Definition: edid-parse.c:34
const GLchar * marker