Multi platform backends for Linux

build.py

@@ -420,6 +420,7 @@ def makeOptionParser():
         ("keep_hash_lines",(False, "Don't remove the '#line N' lines from the SIP generated code")),
         ("gtk2",           (False, "On Linux build for gtk2 (default gtk3)")),
         ("gtk3",           (True,  "On Linux build for gtk3")),
+        ("qt",             (False, "On Linux build for qt")),
         ("osx_cocoa",      (True,  "Build the OSX Cocoa port on Mac (default)")),
         ("osx_carbon",     (False, "Build the OSX Carbon port on Mac (unsupported)")),
         ("mac_framework",  (False, "Build wxWidgets as a Mac framework.")),
@@ -1746,6 +1747,7 @@ def _getWxCompiler(flag, compName, flagName):
         wafBuildDir = posixjoin(wafBuildBase, 'release')
 
     build_options = list()
+    multi_options = list()
     if options.verbose:
         build_options.append('--verbose')
 
@@ -1768,8 +1770,15 @@ def _getWxCompiler(flag, compName, flagName):
             build_options.append('--gtk2')
             wafBuildDir = posixjoin(wafBuildBase, 'gtk2')
         if options.gtk3:
+            if options.qt:
+                # Build qt later
+                build_options.append('--multi')
+                multi_options = build_options[:]
             build_options.append('--gtk3')
             wafBuildDir = posixjoin(wafBuildBase, 'gtk3')
+        if options.qt and not options.gtk3:
+            build_options.append('--qt')
+            wafBuildDir = posixjoin(wafBuildBase, 'qt')
 
     build_options.append('--python="%s"' % PYTHON)
     build_options.append('--out=%s' % wafBuildDir) # this needs to be the last option
@@ -1802,6 +1811,16 @@ def _onWafError():
             msg('*-'*40)
     runcmd(cmd, onError=_onWafError)
 
+    if not isWindows and not isDarwin and options.gtk3 and options.qt:
+        multi_options = [f'{opt}-qt' if 'wx-config' in opt else opt for opt in multi_options]
+        multi_options.append('--qt')
+        wafBuildDir = posixjoin(wafBuildBase, 'qt')
+        multi_options.append('--python="%s"' % PYTHON)
+        multi_options.append('--out=%s' % wafBuildDir)
+
+        cmd = '"%s" %s %s configure build %s' % (PYTHON, waf, ' '.join(multi_options), options.extra_waf)
+        runcmd(cmd, onError=_onWafError)
+
     if isWindows and options.both:
         build_options.remove('--debug')
         del build_options[-1]

src/__init__.py

@@ -11,6 +11,16 @@
 import wx.__version__
 __version__ = wx.__version__.VERSION_STRING
 
+import os
+
+
+# Select platform backend
+__plat__ = '@DEFAULT@'
+if 'WX_API' in os.environ:
+    __plat__ = os.environ['WX_API']
+    if __plat__ not in ['@PLATS@']:
+        raise ImportError(f'invalid WX_API {__plat__}')
+
 
 # Import all items from the core wxPython module so they appear in the wx
 # package namespace.

src/multi.py

@@ -0,0 +1,16 @@
+import importlib
+import sys
+
+root = importlib.import_module(__package__)
+
+_@NAME@ = importlib.import_module(f'.@NAME@_{root.__plat__}', __package__)
+
+if hasattr(_@NAME@, '__all__'):
+    __all__ = _@NAME@.__all__
+else:
+    __all__ = [name for name in dir(_@NAME@) if name != "__name__"]
+
+globals().update({name: getattr(_@NAME@, name) for name in __all__})
+
+del root
+del _@NAME@

wscript

@@ -52,6 +52,10 @@ def options(opt):
                    help='On Linux build for gtk2 (default gtk3)')
     opt.add_option('--gtk3', dest='gtk3', action='store_true', default=True,
                    help='On Linux build for gtk3')
+    opt.add_option('--qt', dest='qt', action='store_true', default=False,
+                   help='On Linux build for qt')
+    opt.add_option('--multi', dest='multi', action='store_true', default=False,
+                   help='On Linux build for multiple backends')
     opt.add_option('--no_msvc', dest='use_msvc', action='store_false', default=isWindows,
                    help='Set to use a MinGW toolchain')
     opt.add_option('--msvc_arch', dest='msvc_arch', default='x86', action='store',
@@ -283,15 +287,27 @@ def configure(conf):
         # wxWidgets.  If we ever support other ports then this code will need
         # to be adjusted.
         if not isDarwin:
+            platflags = ''
             if conf.options.gtk2:
                 conf.options.gtk3 = False
+                conf.options.qt = False
+                conf.options.multi = False
+            if conf.options.qt:
+                conf.options.gtk3 = False
             if conf.options.gtk2:
-                gtkflags = os.popen('pkg-config gtk+-2.0 --cflags', 'r').read()[:-1]
-            else:
-                gtkflags = os.popen('pkg-config gtk+-3.0 --cflags', 'r').read()[:-1]
+                platflags = os.popen('pkg-config gtk+-2.0 --cflags', 'r').read()[:-1]
+            elif conf.options.gtk3:
+                platflags = os.popen('pkg-config gtk+-3.0 --cflags', 'r').read()[:-1]
+            elif conf.options.qt:
+                platflags = os.popen('pkg-config Qt5Core Qt5Gui --cflags', 'r').read()[:-1]
+                conf.options.gtk3 = False
+
+            conf.env.gtk3 = conf.options.gtk3
+            conf.env.qt = conf.options.qt
+            conf.env.multi = conf.options.multi
 
-            conf.env.CFLAGS_WX   += gtkflags.split()
-            conf.env.CXXFLAGS_WX += gtkflags.split()
+            conf.env.CFLAGS_WX   += platflags.split()
+            conf.env.CXXFLAGS_WX += platflags.split()
 
         # clear out Python's default NDEBUG and make sure it is undef'd too just in case
         if 'NDEBUG' in conf.env.DEFINES_PYEXT:
@@ -534,14 +550,31 @@ def build(bld):
     cfg.build_locale_dir(opj(cfg.PKGDIR, 'locale'))
 
     # copy .py files that need to go into the root wx package dir
-    for name in ['src/__init__.py', 'src/gizmos.py',]:
-        copy_file(name, cfg.PKGDIR, update=1, verbose=1)
+    if isWindows:
+        default = 'msw'
+    elif isDarwin:
+        default = 'mac'
+    elif bld.env.gtk2:
+        default = 'gtk2'
+    elif bld.env.gtk3:
+        default = 'gtk3'
+    elif bld.env.qt and not bld.env.multi:
+        default = 'qt'
+    plats = ['gtk3', 'qt'] if bld.env.multi else [default]
+    bld(features='subst', source='src/__init__.py', target='__init__.py', DEFAULT=default, PLATS=str(plats))
+    bld(rule=copyFileToPkg, source='__init__.py', target='pkg.__init__')
+    copy_file('src/gizmos.py', cfg.PKGDIR, update=1, verbose=1)
+
+    extra = dict()
+    plat = ''
+    if not isWindows and not isDarwin and bld.env.multi:
+        plat = '_gtk3' if bld.env.gtk3 else '_qt'
 
     # Create the build tasks for each of our extension modules.
-    addRelwithdebugFlags(bld, 'siplib')
+    addRelwithdebugFlags(bld, f'siplib{plat}')
     siplib = bld(
         features = 'c cxx cshlib cxxshlib pyext',
-        target   = makeTargetName(bld, 'siplib'),
+        target   = makeTargetName(bld, f'siplib{plat}'),
         source   = ['sip/siplib/apiversions.c',
                     'sip/siplib/descriptors.c',
                     'sip/siplib/int_convertors.c',
@@ -553,8 +586,12 @@ def build(bld):
                     'sip/siplib/voidptr.c',
                     ],
         uselib   = 'siplib WX WXPY',
+        **extra,
     )
-    makeExtCopyRule(bld, 'siplib')
+    makeExtCopyRule(bld, f'siplib{plat}')
+    if not isWindows and not isDarwin and bld.env.multi:
+        siplib.env['LDFLAGS'].append_value(f'--defsym=PyInit_siplib{plat}=PyInit_siplib')
+        makeModSubstRule(bld, 'siplib')
 
     # Add build rules for each of our ETG generated extension modules
     makeETGRule(bld, 'etg/_core.py',       '_core',      'WX')
@@ -613,6 +650,17 @@ def makeExtCopyRule(bld, name):
     bld(rule=copyFileToPkg, source=src, target=tgt, after=name)
 
 
+# Make a rule that will copy a multi module to the in-place package
+# dir so we can test locally without doing an install.
+def makeModSubstRule(bld, name):
+    name = makeTargetName(bld, name)
+    subst = f'{name}.py'
+    # just a name to be touched to serve as the timestamp of the copy
+    tgt = 'pkg.%s' % os.path.splitext(subst)[0]
+    bld(features='subst', source='src/multi.py', target=subst, NAME=name)
+    bld(rule=copyFileToPkg, source=subst, target=tgt)
+
+
 # This is the task function to be called by the above rule.
 def copyFileToPkg(task):
     from distutils.file_util import copy_file
@@ -653,6 +701,11 @@ def _copyEnvGroup(env, srcPostfix, destPostfix):
 def makeETGRule(bld, etgScript, moduleName, libFlags):
     from buildtools.config   import loadETG, getEtgSipCppFiles
 
+    extra = dict()
+    if not isWindows and not isDarwin and bld.env.multi:
+        base = moduleName
+        moduleName += '_gtk3' if bld.env.gtk3 else '_qt'
+
     addRelwithdebugFlags(bld, moduleName)
 
     rc = []
@@ -666,12 +719,15 @@ def makeETGRule(bld, etgScript, moduleName, libFlags):
         rc = [rc_name]
 
     etg = loadETG(etgScript)
-    bld(features='c cxx cxxshlib pyext',
+    mod = bld(features='c cxx cxxshlib pyext',
         target=makeTargetName(bld, moduleName),
         source=getEtgSipCppFiles(etg) + rc,
         uselib='{} {} WXPY'.format(moduleName, libFlags),
-        )
+        **extra)
     makeExtCopyRule(bld, moduleName)
+    if not isWindows and not isDarwin and bld.env.multi:
+        mod.env['LDFLAGS'].append_value(f'--defsym=PyInit_{moduleName}=PyInit_{base}')
+        makeModSubstRule(bld, base)
 
 
 # Add flags to create .pdb files for debugging with MSVC