mirrors/fltk
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Ensure that exporting 'fl_disable_wayland' works

Browse Source 
... with cmake_minimum_required(VERSION 3.4) or higher. This version
sets CMP0065 to 'NEW' which by default inhibits exporting global
symbols from executable programs.

For details see CMake policy CMP0065 and README.Wayland.txt.
This commit is contained in:
Albrecht Schlosser 2023-12-21 19:13:49 +01:00
parent fcf91e51c0
commit 007e37d897
2 changed files with 65 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
CMake/fl_create_example.cmake
View File

@ -119,6 +119,11 @@ function (CREATE_EXAMPLE NAME SOURCES LIBRARIES)
set_target_properties (${TARGET_NAME} PROPERTIES OUTPUT_NAME ${NAME})
target_link_libraries (${TARGET_NAME} ${LIBRARIES})
# make sure we're "exporting" global symbols like 'fl_disable_wayland',
# see also README.Wayland.txt and CMake policy CMP0065.
set_target_properties (${TARGET_NAME} PROPERTIES ENABLE_EXPORTS TRUE)
# we must link all programs with cairo if option CAIROEXT is enabled
if (FLTK_HAVE_CAIROEXT)
target_link_libraries (${TARGET_NAME} ${PKG_CAIRO_LIBRARIES})

71
README.Wayland.txt
View File

@ -8,8 +8,9 @@ Contents
1 Introduction
2 Wayland Support for FLTK
2.1 Configuration
2.2 Known Limitations
2.1 Disabling Wayland for Backwards Compatibility
2.2 Configuration
2.3 Known Limitations
3 Platform Specific Notes
3.1 Debian and Derivatives (like Ubuntu, Mint, RaspberryPiOS)
@ -49,17 +50,65 @@ X11 is used at run time as follows:
compositor is available;
- if $FLTK_BACKEND has another value, the library stops with error.
Alternatively, it is possible to force a program linked to a Wayland-enabled
FLTK library to use X11 in all situations by putting this declaration somewhere
in the source code :
FL_EXPORT bool fl_disable_wayland = true;
FLTK source code and also X11-specific source code conceived for FLTK 1.3
should run with a Wayland-enabled, FLTK 1.4 library with that single change only.
On pure Wayland systems without the X11 headers and libraries, FLTK can be built
with its Wayland backend only (see below).
2.1 Configuration
2.1 Disabling Wayland for Backwards Compatibility
---------------------------------------------------
Programs using X11 specific functions may need to disable the automatic
detection of Wayland at runtime so they fall back to X11 only.
It is possible to force a program linked to a Wayland-enabled FLTK library
to use X11 in all situations by putting this declaration somewhere in the
source code:
FL_EXPORT bool fl_disable_wayland = true;
FLTK source code and also X11-specific source code conceived for FLTK 1.3
should run with a Wayland-enabled FLTK 1.4 library with this single change.
Caveat: when building a user project with the requirement to use CMake
version 3.4 or higher, i.e. using
cmake_minimum_required (VERSION 3.4)
or any higher (minimum) CMake version users need to use at least one of
the following options:
Option 1: Set target property 'ENABLE_EXPORTS' on all executable
targets that require it to disable the Wayland backend.
This is the preferred solution.
CMake example:
set_target_properties(prog PROPERTIES ENABLE_EXPORTS TRUE)
Option 2: Set CMake policy CMP0065 to 'OLD' (to pre-3.4 behavior)
This is a quick solution but discouraged because setting
CMake policies to 'OLD' is deprecated by definition.
CMake code:
cmake_policy(SET CMP0065 OLD)
Option 3: Set CMake variable 'CMAKE_ENABLE_EXPORTS' to 'TRUE'.
Note: use this to be compatible with CMake < 3.27.
Option 4: Set CMake variable 'CMAKE_EXECUTABLE_ENABLE_EXPORTS' to 'TRUE'.
Note: new in CMake 3.27, ignored in older versions.
Options 3 and 4 can be used as quick solutions like option 2 but these
options affect all targets that are created while the CMake variable is
set. As said above, option 1 should be preferred.
This applies to the FLTK test and demo programs as well, hence we use
option 1 in our build system.
2.2 Configuration
------------------
On Linux and FreeBSD systems equipped with the adequate software packages
@ -85,7 +134,7 @@ Mutter (gnome's Wayland compositor) and Weston use CSD mode, KWin and Sway use S
Furthermore, setting environment variable LIBDECOR_FORCE_CSD to 1 will make FLTK use CSD
mode even if the compositor would have selected SSD mode.
2.2 Known Limitations
2.3 Known Limitations
----------------------
* A deliberate design trait of Wayland makes application windows ignorant of their exact