docs/microwin/readme.txt

   1 wxMicroWindows port
   2 ===================
   3
   4 Julian Smart 2001-12-08
   5
   6 This is a port of wxWindows to MicroWindows, under Linux.
   7 Widgets are supplied by the wxUniversal project, while the
   8 underlying port uses the Windows ports with small modifications
   9 for the MicroWindows API.
  10
  11 There are many things missing from MicroWindows that will
  12 make the port quite limited for the time being. I haven't
  13 worked out how to create bitmaps, though there is a BMP to C
  14 converter. There are no common dialogs (we will use generic ones),
  15 and only one WIN32 app may be run at a time.
  16
  17 Note that you can gain confidence in the WIN32/wxUniversal
  18 combination by compiling wxUniversal under Windows using VC++,
  19 using src/wxvc_universal.dsp. You can compile the minimal
  20 and widgets samples in wxUniversal mode using the
  21 UnivDebug and UnivRelease targets. Most of the code is shared
  22 between this combination, and the wxMicroWindows port.
  23
  24 Installation
  25 ============
  26
  27 MicroWindows:
  28
  29 - unarchive MicroWindows 0.89pre8
  30
  31 - change 'config' to use X11 and any other options you feel fit.
  32   Suggestions for changes to the defaults:
  33
  34   ERASEMOVE=N (otherwise moving windows will look messy)
  35   X11=Y
  36   OPTIMIZE=N
  37   DEBUG=Y
  38   VERBOSE=Y
  39
  40   Note: these are already applied by the patch below.
  41
  42 - apply microwindows.patches (from wxWindows:
  43   docs/microwin/microwindows.patches) to fix PeekMessage
  44   and other issues. If the patch doesn't apply automatically,
  45   you may need to apply it by hand, and the relevant changed
  46   functions are given at the end of this file for convenience.
  47
  48   Example patch command:
  49
  50   % cd microwindows-0.89pre8.orig
  51   % patch -p0 < ~/wx2/docs/microwin/microwindows.patches
  52
  53 - compile by typing 'make' from within the MicroWindows src directory
  54
  55 wxMicroWindows:
  56
  57 - Download wxMSW 2.3.2 or greater, or get it from CVS
  58
  59 - Copy include/wx/msw/setup_microwin.h to include/wx/setup.h if
  60   include/wx/setup.h doesn't exist
  61
  62 - EITHER:
  63
  64   o set the MICROWINDOWS environment variable, e.g.:
  65
  66     % export MICROWINDOWS=/home/julians/local/microwindows/microwindows-0.89pre8/src
  67
  68   OR:
  69
  70   o change the TOP variable at the top of src/msw/makefile.mic
  71     to reflect where MicroWindows is installed
  72
  73 - type 'make -f makefile.mic all' from src/msw. To clean, use
  74   cleanwx and NOT clean since that will clean MicroWindows itself
  75
  76 - to make the sample, cd into samples/minimal, edit the TOP variable
  77   (or set MICROWINDOWS) as before, and type 'make -f makefile.mic all'
  78
  79 Running 'minimal' runs the virtual MicroWindows desktop
  80 and the minimal sample, since in a MicroWindows WIN32 application
  81 they are one and the same binary.
  82
  83 Status
  84 ======
  85
  86 The minimal sample is almost fully-functional, apart from minor
  87 menu presentation issues (no borders, for example).
  88
  89 Implementation Notes
  90 ====================
  91
  92 wxMicroWindows is essentially the wxMSW port + wxUniversal
  93 widgets. Lots of things in include/wx/univ/setup.h are switched
  94 off to allow the port to compile. There are also #ifdefs
  95 switching off further functionality, such as most wxBitmap
  96 functions, pending proper implementation.
  97
  98 There are some WIN32 API functions not implemented by MicroWindows
  99 that are instead stubbed out in include/wx/msw/microwin.c,
 100 and 'implemented' in src/msw/microwin.c. Some of these functions
 101 are important, some less so. They will need to be implemented
 102 in due course. But implementing missing functionality in this way
 103 is preferably to proliferating many #ifdefs in the
 104 wxMSW/wxMicroWindows port itself.
 105
 106 Things missing from MicroWindows that need to be worked around
 107 ==============================================================
 108
 109 wxImage/inline XPM/::CreateBitmap support
 110 -----------------------------------------
 111
 112 This is the main obstacle to getting a good range
 113 of widgets working, since wxUniversal uses inline XPMs
 114 to implement most of the widgets.
 115
 116 See src/engine/devimage.c for routines for loading JPEGs,
 117 XPMs etc. Unfortunately the XPM routines are also #ifdefed
 118 for FILE_IO, even though for inline XPMs we don't need file I/O.
 119 (Embedded systems tend not to have file I/O, anyway.)
 120
 121 Now, wxWindows has its own XPM decoder, src/common/xpmdecod.cpp,
 122 so in theory we don't need to use MicroWindows' code there.
 123 wxImage can load an inline XPM, _but_ we need to convert to
 124 a wxBitmap since this is what the widgets need.
 125
 126 There is no ::CreateBitmap or BITMAPINFO. (BMPs can be converted
 127 to C using convbmp, then need to use Gr... functions.)
 128
 129 So how can we convert from wxImage to wxBitmap in MicroWindows?
 130
 131 Well, a simple-minded way would be to use CreateCompatibleBitmap
 132 which returns an HBITMAP, select it into an HDC, and draw
 133 the pixels from the wxImage to the HDC one by one with SetPixel.
 134
 135
 136 Other missing features
 137 ----------------------
 138
 139 No ::GetKeyState (see include/wx/msw/private.h). Should probably use
 140 GdOpenKeyboard/GdCloseKeyboard/GdReadKeyboard. Could perhaps emulate
 141 GetKeyState this way.
 142
 143 No ::DestroyIcon, ::DestroyCursor - use ::DestroyObject instead?
 144 Also no LoadCursor, LoadImage. So how do we make cursors? No ::SetCursor.
 145
 146 wxDC: no ::GetTextColor, ::GetBkColor, ::IntersectClipRect,
 147 ::GetClipBox
 148
 149 No ::SetMenu, so no menus or menubars (now implemented by
 150 wxUniversal).
 151
 152 No ::GetObject so we can't get LOGFONT from an HFONT
 153 in wxSystemSettings (worked around by passing HFONT to
 154 the wxFont constructor).
 155
 156
 157 Applying patches by hand
 158 ========================
 159
 160 The full altered functions are given below in case you have
 161 to apply them by hand.
 162
 163 src/mwin/winevent.c
 164 -------------------
 165
 166 A second test has been added to this line:
 167
 168         if(hittest == HTCLIENT || hwnd == GetCapture()) {
 169
 170 in MwTranslateMouseMessage below. This corrects a mouse message
 171 bug.
 172
 173 /*
 174  * Translate and deliver hardware mouse message to proper window.
 175  */
 176 void
 177 MwTranslateMouseMessage(HWND hwnd,UINT msg,int hittest)
 178 {
 179         POINT           pt;
 180         DWORD           tick;
 181         static UINT     lastmsg = 0;
 182         static HWND     lasthwnd;
 183         static DWORD    lasttick;
 184         static int      lastx, lasty;
 185
 186         /* determine double click eligibility*/
 187         if(msg == WM_LBUTTONDOWN || msg == WM_RBUTTONDOWN) {
 188                 tick = GetTickCount();
 189                 if((hwnd->pClass->style & CS_DBLCLKS) &&
 190                     msg == lastmsg && hwnd == lasthwnd &&
 191                     tick - lasttick < DBLCLICKSPEED &&
 192                     abs(cursorx-lastx) < mwSYSMETRICS_CXDOUBLECLK &&
 193                     abs(cursory-lasty) < mwSYSMETRICS_CYDOUBLECLK)
 194                         msg += (WM_LBUTTONDBLCLK - WM_LBUTTONDOWN);
 195                 lastmsg = msg;
 196                 lasthwnd = hwnd;
 197                 lasttick = tick;
 198                 lastx = cursorx;
 199                 lasty = cursory;
 200         }
 201
 202         /*
 203          * We always send nc mouse message
 204          * unlike Windows, for HTCLIENT default processing
 205          */
 206         PostMessage(hwnd, msg + (WM_NCMOUSEMOVE-WM_MOUSEMOVE), hittest,
 207                 MAKELONG(cursorx, cursory));
 208
 209         /* then possibly send user mouse message*/
 210         if(hittest == HTCLIENT || hwnd == GetCapture()) {
 211                 pt.x = cursorx;
 212                 pt.y = cursory;
 213                 ScreenToClient(hwnd, &pt);
 214                 PostMessage(hwnd, msg, 0, MAKELONG(pt.x, pt.y));
 215         }
 216 }
 217
 218 winuser.c
 219 ---------
 220
 221 Part of PeekMessage has been factored out into PeekMessageHelper,
 222 and used in PeekMessage and GetMessage. The three relevant functions
 223 are:
 224
 225 /*
 226  * A helper function for sharing code between PeekMessage and GetMessage
 227  */
 228
 229 BOOL WINAPI
 230 PeekMessageHelper(LPMSG lpMsg, HWND hwnd, UINT uMsgFilterMin, UINT uMsgFilterMax,
 231         UINT wRemoveMsg, BOOL returnIfEmptyQueue)
 232 {
 233         HWND    wp;
 234         PMSG    pNxtMsg;
 235
 236         /* check if no messages in queue*/
 237         if(mwMsgHead.head == NULL) {
 238                 /* Added by JACS so it doesn't reach MwSelect */
 239                 if (returnIfEmptyQueue)
 240                     return FALSE;
 241
 242 #if PAINTONCE
 243                 /* check all windows for pending paint messages*/
 244                 for(wp=listwp; wp; wp=wp->next) {
 245                         if(!(wp->style & WS_CHILD)) {
 246                                 if(chkPaintMsg(wp, lpMsg))
 247                                         return TRUE;
 248                         }
 249                 }
 250                 for(wp=listwp; wp; wp=wp->next) {
 251                         if(wp->style & WS_CHILD) {
 252                                 if(chkPaintMsg(wp, lpMsg))
 253                                         return TRUE;
 254                         }
 255                 }
 256 #endif
 257                 MwSelect();
 258         }
 259
 260         if(mwMsgHead.head == NULL)
 261                 return FALSE;
 262
 263         pNxtMsg = (PMSG)mwMsgHead.head;
 264         if(wRemoveMsg & PM_REMOVE)
 265                 GdListRemove(&mwMsgHead, &pNxtMsg->link);
 266         *lpMsg = *pNxtMsg;
 267         if(wRemoveMsg & PM_REMOVE)
 268                 GdItemFree(pNxtMsg);
 269         return TRUE;
 270 }
 271
 272 BOOL WINAPI
 273 PeekMessage(LPMSG lpMsg, HWND hwnd, UINT uMsgFilterMin, UINT uMsgFilterMax,
 274         UINT wRemoveMsg)
 275 {
 276         /* Never wait in MwSelect: pass TRUE */
 277         return PeekMessageHelper(lpMsg, hwnd, uMsgFilterMin, uMsgFilterMax, wRemoveMsg, TRUE);
 278 }
 279
 280 BOOL WINAPI
 281 GetMessage(LPMSG lpMsg,HWND hwnd,UINT wMsgFilterMin,UINT wMsgFilterMax)
 282 {
 283         /*
 284          * currently MwSelect() must poll for VT switch reasons,
 285          * so this code will work
 286          */
 287         /* Always wait in MwSelect if there are messages: pass FALSE */
 288         while(!PeekMessageHelper(lpMsg, hwnd, wMsgFilterMin, wMsgFilterMax,PM_REMOVE, FALSE))
 289                 continue;
 290         return lpMsg->message != WM_QUIT;
 291 }