Add ecm_add_app_icon function.

This adds an application icon to an executable from PNG files for
Windows and Mac OS X. Unlike the similar kde4_add_app_icon macro from
kdelibs, this requires icons to be explicitly listed as arguments
(meaning CMake can tell when ones are added or deleted and reconfigure
as appropriate), and it works with Matthias Benkmann's png2ico tool, as
well as the KDE-Win tool of the same name.

Currently missing unit tests. Also completely untested (except that
`make test` runs on Linux, so there are no obvious syntax errors).

With thanks to Ralf Habacker for the inital work on porting
kde4_add_app_icon.

CHANGELOG: Add ECMAddAppIcon module to add icons to executable targets
on Windows and Mac OS X.

1 files changed, 115 insertions, 0 deletions

diff --git a/find-modules/FindPng2Ico.cmake b/find-modules/FindPng2Ico.cmake
new file mode 100644
index 00000000..71e2487c
--- /dev/null
+++ b/find-modules/FindPng2Ico.cmake
@@ -0,0 +1,115 @@
+#.rst:
+# FindPng2Ico
+# -----------
+#
+# Try to find png2ico.
+#
+# If the png2ico executable is not in your PATH, you can provide
+# an alternative name or full path location with the ``Png2Ico_EXECUTABLE``
+# variable.
+#
+# This will define the following variables:
+#
+# ``Png2Ico_FOUND``
+#     True if png2ico is available.
+#
+# ``Png2Ico_EXECUTABLE``
+#     The png2ico executable.
+#
+# If ``Png2Ico_FOUND`` is TRUE, it will also define the following imported
+# target:
+#
+# ``Png2Ico::Png2Ico``
+#     The png2ico executable.
+#
+# and the following variables:
+#
+# ``Png2Ico_HAS_COLORS_ARGUMENT``
+#     Whether png2ico accepts a ``--colors`` argument. `Matthias Benkmann's
+#     tool <http://www.winterdrache.de/freeware/png2ico/>`_ does, while the
+#     version of png2ico from the `"KDE On Windows" (kdewin)
+#     <https://projects.kde.org/projects/kdesupport/kdewin>`_ project does not.
+#
+# ``Png2Ico_HAS_RCFILE_ARGUMENT``
+#     Whether png2ico accepts an ``--rcfile`` argument. The version of png2ico
+#     from the `"KDE On Windows" (kdewin)
+#     <https://projects.kde.org/projects/kdesupport/kdewin>`_ project does,
+#     while `Matthias Benkmann's tool
+#     <http://www.winterdrache.de/freeware/png2ico/>`_ does not.
+#
+
+#=============================================================================
+# Copyright 2014 Alex Merry <alex.merry@kde.org>
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+#
+# 1. Redistributions of source code must retain the copyright
+#    notice, this list of conditions and the following disclaimer.
+# 2. Redistributions in binary form must reproduce the copyright
+#    notice, this list of conditions and the following disclaimer in the
+#    documentation and/or other materials provided with the distribution.
+# 3. The name of the author may not be used to endorse or promote products
+#    derived from this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+# IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+# OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+# IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+# NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+# THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#=============================================================================
+
+include(${CMAKE_CURRENT_LIST_DIR}/ECMFindModuleHelpersStub.cmake)
+
+ecm_find_package_version_check(Png2Ico)
+
+# Find png2ico
+find_program(Png2Ico_EXECUTABLE NAMES png2ico)
+
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(Png2Ico
+    FOUND_VAR
+        Png2Ico_FOUND
+    REQUIRED_VARS
+        Png2Ico_EXECUTABLE
+)
+
+mark_as_advanced(Png2Ico_EXECUTABLE)
+
+if (Png2Ico_FOUND)
+    execute_process(
+        COMMAND "${Png2Ico_EXECUTABLE}" --help
+        OUTPUT_VARIABLE _png2ico_help_text
+    )
+    if (_png2ico_help_text MATCHES ".*--rcfile .*")
+        set(Png2Ico_HAS_RCFILE_ARGUMENT TRUE)
+    else()
+        set(Png2Ico_HAS_RCFILE_ARGUMENT FALSE)
+    endif()
+    if (_png2ico_help_text MATCHES ".*--colors .*")
+        set(Png2Ico_HAS_COLORS_ARGUMENT TRUE)
+    else()
+        set(Png2Ico_HAS_COLORS_ARGUMENT FALSE)
+    endif()
+    unset(_png2ico_help_text)
+
+    if (NOT TARGET Png2Ico::Png2Ico)
+        add_executable(Png2Ico::Png2Ico IMPORTED)
+        set_target_properties(Png2Ico::Png2Ico PROPERTIES
+            IMPORTED_LOCATION "${Png2Ico_EXECUTABLE}"
+        )
+    endif()
+endif()
+
+include(FeatureSummary)
+set_package_properties(Png2Ico PROPERTIES
+    URL "http://www.winterdrache.de/freeware/png2ico/ or https://projects.kde.org/projects/kdesupport/kdewin"
+    DESCRIPTION "Executable that converts a collection of PNG files into a Windows icon file"
+)
+