Always send an erase event to satisfy some users...

[wxWidgets.git] / docs / microwin / readme.txt

diff --git a/docs/microwin/readme.txt b/docs/microwin/readme.txt
index 8cd81015a8b20825be82fbe775b52aa3613ee708..e916ced79455097180c49bebf18ac1632bd7b65f 100644 (file)
--- a/docs/microwin/readme.txt
+++ b/docs/microwin/readme.txt
@@ -59,14 +59,22 @@ wxMicroWindows:
 - Copy include/wx/msw/setup_microwin.h to include/wx/setup.h if
   include/wx/setup.h doesn't exist
 
-- change the TOP variable at the top of src/msw/makefile.mic
-  to reflect where MicroWindows is installed
+- EITHER:
+
+  o set the MICROWINDOWS environment variable, e.g.:
+
+    % export MICROWINDOWS=/home/julians/local/microwindows/microwindows-0.89pre8/src
+
+  OR:
+
+  o change the TOP variable at the top of src/msw/makefile.mic
+    to reflect where MicroWindows is installed
 
 - type 'make -f makefile.mic all' from src/msw. To clean, use
   cleanwx and NOT clean since that will clean MicroWindows itself
 
-- to make the sample, cd into samples/minimal, edit the TOP variable,
-  and type 'make -f makefile.mic all'
+- to make the sample, cd into samples/minimal, edit the TOP variable
+  (or set MICROWINDOWS) as before, and type 'make -f makefile.mic all'
 
 Running 'minimal' runs the virtual MicroWindows desktop
 and the minimal sample, since in a MicroWindows WIN32 application
@@ -75,8 +83,12 @@ they are one and the same binary.
 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
 ====================
@@ -95,20 +107,76 @@ in due course. But implementing missing functionality in this way
 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, wxWindows 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.