Julian Smart 2001-12-08
-This is a port of wxWindows to MicroWindows, under Linux.
+This is a port of wxWidgets to MicroWindows, under Linux.
Widgets are supplied by the wxUniversal project, while the
underlying port uses the Windows ports with small modifications
for the MicroWindows API.
+=== NOTE: ===
+
+ Current efforts are being concentrated on a port to Nano-X,
+ which potentially offers greater flexibility than the WIN32
+ API of MicroWindows, such as the ability to run multiple
+ Nano-X processes simultaneously. Please see
+ ../docs/x11/readme-nanox.txt for information.
+
There are many things missing from MicroWindows that will
-make the port quite limited for the time being. I haven't
-worked out how to create bitmaps, though there is a BMP to C
-converter. There are no common dialogs (we will use generic ones),
-and only one WIN32 app may be run at a time.
+make the port quite limited for the time being.
+In particular, only one WIN32 app may be run at a time.
Note that you can gain confidence in the WIN32/wxUniversal
combination by compiling wxUniversal under Windows using VC++,
-using src/wxvc_universal.dsp. You can compile the minimal
+using src/wxUniv.dsp. You can compile the minimal
and widgets samples in wxUniversal mode using the
UnivDebug and UnivRelease targets. Most of the code is shared
between this combination, and the wxMicroWindows port.
Note: these are already applied by the patch below.
-- apply microwindows.patches (from wxWindows:
+- apply microwindows.patches (from wxWidgets:
docs/microwin/microwindows.patches) to fix PeekMessage
and other issues. If the patch doesn't apply automatically,
you may need to apply it by hand, and the relevant changed
wxMicroWindows:
-- Download wxMSW 2.3.2 or greater, or get it from CVS
+- Download wxMSW 2.3.4 or greater, or get it from CVS
- Copy include/wx/msw/setup_microwin.h to include/wx/setup.h if
include/wx/setup.h doesn't exist
Status
======
-The minimal sample is almost fully-functional, apart from minor
-menu presentation issues (no borders, for example).
+The minimal sample is almost fully-functional, apart from some
+presentation issues (no menu borders and status bar in the wrong
+place.
+
+The widgets sample is crashing in DeleteObject (see notes below).
+
Implementation Notes
====================
is preferably to proliferating many #ifdefs in the
wxMSW/wxMicroWindows port itself.
+
+Errors/warnings
+===============
+
+In file ../../src/msw/window.cpp at line 1294: 'UpdateWindow' failed with error 0x00000000 (Success).
+
+ - caused because there are no paint messages pending. Presumed
+ harmless.
+
+In file ../../src/msw/dc.cpp at line 1838: 'BitBlt' failed with error 0x00000000 (Success).
+
+ - caused because the window isn't mapped, and MwPrepareDC in wingdi.c
+ fails (hwnd->unmapcount is non-zero). Presumed harmless.
+
+Recursive paint problem, e.g. when clicking the 'Press Me!'
+button in the widgets sample a few times, until the text control
+is full.
+
+ - possibly the scrollbar is causing the text control to be
+ updated, which somehow effects the scrollbar, which causes
+ a window update, etc.
+
+Sluggish updates.
+
+ - probably because many image to bitmap conversions are being
+ done on update, and bitmaps should probably be cached.
+
+
Things missing from MicroWindows that need to be worked around
==============================================================
+wxImage/inline XPM/::CreateBitmap support
+-----------------------------------------
+
+This is the main obstacle to getting a good range
+of widgets working, since wxUniversal uses inline XPMs
+to implement most of the widgets.
+
+See src/engine/devimage.c for routines for loading JPEGs,
+XPMs etc. Unfortunately the XPM routines are also #ifdefed
+for FILE_IO, even though for inline XPMs we don't need file I/O.
+(Embedded systems tend not to have file I/O, anyway.)
+
+Now, wxWidgets has its own XPM decoder, src/common/xpmdecod.cpp,
+so in theory we don't need to use MicroWindows' code there.
+wxImage can load an inline XPM, _but_ we need to convert to
+a wxBitmap since this is what the widgets need.
+
+There is no ::CreateBitmap or BITMAPINFO. (BMPs can be converted
+to C using convbmp, then need to use Gr... functions.)
+
+So how can we convert from wxImage to wxBitmap in MicroWindows?
+
+Well, a simple-minded way would be to use CreateCompatibleBitmap
+which returns an HBITMAP, select it into an HDC, and draw
+the pixels from the wxImage to the HDC one by one with SetPixel.
+This is now implemented, but there are problems with masks.
+(a) masks have to be created at screen depth because BitBlt/GrDraw
+can't cope with differing depths, and (b) masked blitting
+is still not working (try enabling mask creation in
+wxBitmap::CreateFromImage by setting USE_MASKS to 1).
+
+
+Other missing features
+----------------------
+
No ::GetKeyState (see include/wx/msw/private.h). Should probably use
GdOpenKeyboard/GdCloseKeyboard/GdReadKeyboard. Could perhaps emulate
GetKeyState this way.
-No ::CreateBitmap or BITMAPINFO. But BMPs can be converted
-to C using convbmp, then need to use Gr... functions.
-We MUST implement creation from XPMs, since wxUniversal
-makes use of XPMs, or else create our own bitmaps for
-drawing radioboxes, checkboxes etc.: see renderers
-in src/univ.
-
No ::DestroyIcon, ::DestroyCursor - use ::DestroyObject instead?
Also no LoadCursor, LoadImage. So how do we make cursors? No ::SetCursor.