Remove logic for optionally building Agg and TkAgg.

anntzer · anntzer · commit ac3d800598af · 2019-05-27T11:07:08.000+02:00
They are actually not optional (that's the `force = True` setting which
overrides the OptionalBackendPackage logic), so just make them
SetupPackages and remove the corresponding (outdated) comments in
setup.cfg.template.
diff --git a/setup.cfg.template b/setup.cfg.template
@@ -24,25 +24,10 @@
 #sample_data = True
 
 [gui_support]
-# Matplotlib supports multiple GUI toolkits, including
-# GTK3, MacOSX, Qt4, Qt5, Tk, and WX. Support for many of
-# these toolkits requires AGG, the Anti-Grain Geometry library,
-# which is provided by Matplotlib and built by default.
-#
-# Some backends are written in pure Python, and others require
-# extension code to be compiled. By default, Matplotlib checks for
-# these GUI toolkits during installation and, if present, compiles the
-# required extensions to support the toolkit.
-#
-# - Tk support requires Tk development headers and Tkinter.
-# - Mac OSX backend requires the Cocoa headers included with XCode.
-#
-# The other GUI toolkits do not require any extension code, and can be
-# used as long as the libraries are installed on your system --
-# therefore they are installed unconditionally.
-#
-# You can uncomment any the following lines to change this
-# behavior. Acceptable values are:
+# Matplotlib supports multiple GUI toolkits, known as backends.
+# The Mac OSX backend requires the Cocoa headers included with XCode.
+# You can select whether to build it by uncommenting the following line.
+# Acceptable values are:
 #
 #     True: build the extension. Exits with a warning if the
 #           required dependencies are not available
@@ -51,9 +36,7 @@
 #           otherwise skip silently. This is the default
 #           behavior
 #
-#agg = auto
 #macosx = auto
-#tkagg = auto
 
 [rc_options]
 # User-configurable options
diff --git a/setupext.py b/setupext.py
@@ -411,7 +411,6 @@ def _try_managers(*managers):
 
 class OptionalPackage(SetupPackage):
     optional = True
-    force = False
     config_category = "packages"
     default_config = "auto"
 
@@ -437,26 +436,13 @@ def check(self):
 
         May be overridden by subclasses for additional checks.
         """
-        # Check configuration file
-        conf = self.get_config()
-        # Default "auto" state or install forced by user
-        if conf in [True, 'auto']:
-            # Set non-optional if user sets `True` in config
-            if conf is True:
+        conf = self.get_config()  # Check configuration file
+        if conf in [True, 'auto']:  # Default "auto", or install forced by user
+            if conf is True:  # Set non-optional if user sets `True` in config
                 self.optional = False
             return "installing"
-        # Configuration opt-out by user
-        else:
-            # Some backend extensions (e.g. Agg) need to be built for certain
-            # other GUI backends (e.g. TkAgg) even when manually disabled
-            if self.force is True:
-                return "installing forced (config override)"
-            else:
-                raise CheckFailed("skipping due to configuration")
-
-
-class OptionalBackendPackage(OptionalPackage):
-    config_category = "gui_support"
+        else:  # Configuration opt-out by user
+            raise CheckFailed("skipping due to configuration")
 
 
 class Platform(SetupPackage):
@@ -871,9 +857,8 @@ def get_extension(self):
         return ext
 
 
-class BackendAgg(OptionalBackendPackage):
+class BackendAgg(SetupPackage):
     name = "agg"
-    force = True
 
     def get_extension(self):
         sources = [
@@ -889,9 +874,8 @@ def get_extension(self):
         return ext
 
 
-class BackendTkAgg(OptionalBackendPackage):
+class BackendTkAgg(SetupPackage):
     name = "tkagg"
-    force = True
 
     def check(self):
         return "installing; run-time loading from Python Tcl/Tk"
@@ -919,7 +903,8 @@ def add_flags(self, ext):
             ext.libraries.extend(['dl'])
 
 
-class BackendMacOSX(OptionalBackendPackage):
+class BackendMacOSX(OptionalPackage):
+    config_category = 'gui_support'
     name = 'macosx'
 
     def check(self):
@@ -938,15 +923,12 @@ def get_extension(self):
         return ext
 
 
-class OptionalPackageData(OptionalPackage):
-    config_category = "package_data"
-
-
-class Dlls(OptionalPackageData):
+class Dlls(OptionalPackage):
     """
     On Windows, this packages any DLL files that can be found in the
     lib/matplotlib/* directories.
     """
+    config_category = "package_data"
     name = "dlls"
 
     def check(self):
