Development/Tutorials/Icons: Difference between revisions

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{{Review|Port to KF5}}
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[[File:Snapshot-krep-arrow.png]]
[[File:Snapshot-krep-arrow.png]]


These icons are called [http://api.kde.org/4.x-api/kdelibs-apidocs/kdeui/html/classKIcon.html KIcon]s. This article shows you how to do this on the example of the software [http://www.staerk.de/thorsten/krep krep]. In case of a [[Development/Tutorials/CMake|
These icons are called [http://api.kde.org/4.x-api/kdelibs-apidocs/kdeui/html/classKIcon.html KIcon]s. This article shows you how to do this using the software [http://www.staerk.de/thorsten/krep krep] as an example. In case of a [[Development/Tutorials/CMake|
cmake]] based project you will need to   
CMake]]-based project you will need to   
* [http://websvn.kde.org/trunk/playground/utils/krep/main.cpp?r1=1154359&r2=1249871 modify main.cpp (as it is typically called)]
* [http://websvn.kde.org/trunk/playground/utils/krep/main.cpp?r1=1154359&r2=1249871 modify main.cpp (as it is typically called)]
* [http://websvn.kde.org/trunk/playground/utils/krep/CMakeLists.txt?r1=813330&r2=1249871&sortby=date modify CMakeLists.txt]
* [http://websvn.kde.org/trunk/playground/utils/krep/CMakeLists.txt?r1=813330&r2=1249871&sortby=date modify CMakeLists.txt]


How to use icons in a qmake base project is discussed [http://appdeveloper.intel.com/en-us/Qt%20C%20Plus%20Plus%20app%20MeeGo%20SDK elsewhere].
How to use icons in QMake-based projects is discussed [http://appdeveloper.intel.com/en-us/Qt%20C%20Plus%20Plus%20app%20MeeGo%20SDK elsewhere].


= Your KDE project =
= Your KDE project =
If you have a KDE project and want to use icons within it, and want that these icons install seamlessly, you will have to name the icons after the project. In the following we look at a project named ''krep''. The important lines in CMakeLists.txt are the ones printed bold below:
If you have a KDE project and want to use icons within it, and want these icons installed seamlessly, you will have to name the icons after the project. In the following we look at a project named ''krep''. The important lines in CMakeLists.txt are the ones printed bold below:
PROJECT( krep )
<syntaxhighlight lang="cmake">
FIND_PACKAGE( KDE4 REQUIRED )
PROJECT( krep )
INCLUDE_DIRECTORIES( ${KDE4_INCLUDES} . )
FIND_PACKAGE( KDE4 REQUIRED )
INCLUDE_DIRECTORIES( ${KDE4_INCLUDES} . )
   
   
SET(krepSources main.cpp krep.cpp krep.h)
SET( krepSources main.cpp krep.cpp krep.h )
   
   
qt4_add_dbus_adaptor( krepSources  
qt4_add_dbus_adaptor( krepSources  
                      org.kde.krep.xml
                      org.kde.krep.xml
                      krep.h
                      krep.h
                      krep
                      krep
                      mainadaptor
                      mainadaptor
                      MainAdaptor )
                      MainAdaptor )
   
   
kde4_add_ui_files( krepSources krepui.ui )
kde4_add_ui_files( krepSources krepui.ui )
   
   
'''[[Development/CMake/Addons_for_KDE#Macros|kde4_add_app_icon]]( krepSources "hi*-app-krep.png" )'''
kde4_add_app_icon( krepSources "hi*-app-krep.png" )
   
   
KDE4_ADD_EXECUTABLE( krep ${krepSources} )
KDE4_ADD_EXECUTABLE( krep ${krepSources} )
   
   
TARGET_LINK_LIBRARIES( krep ${KDE4_KPARTS_LIBS} )
TARGET_LINK_LIBRARIES( krep ${KDE4_KPARTS_LIBS} )
   
   
install( TARGETS krep ${INSTALL_TARGETS_DEFAULT_ARGS} )
install( TARGETS krep ${INSTALL_TARGETS_DEFAULT_ARGS} )
   
   
'''kde4_install_icons( ${[[Development/CMake/Addons_for_KDE#The_locations_of_install_directories|ICON_INSTALL_DIR]]} )'''
kde4_install_icons( ${ICON_INSTALL_DIR} )
</syntaxhighlight>
Weitere Informationen:
* [[Development/CMake/Addons_for_KDE#Macros|kde4_add_app_icon]]
* [[Development/CMake/Addons_for_KDE#The_locations_of_install_directories|ICON_INSTALL_DIR]]


= How to test it =
= How to test it =
* delete a file
The easy way is to define a custom cmake install prefix where you can simply insall the project without touching your system.
rm /usr/local/share/icons/hicolor/22x22/apps/krep.png  
Use following commands to setup this:
* delete your cache
 
rm -rf /var/tmp/kdecache-''user''/
<syntaxhighlight lang="bash">
* relogin
cd build
cmake -DCMAKE_INSTALL_PREFIX=$HOME/playground ../
make && make install
</syntaxhighlight>
 
now the files should be deployed under
<syntaxhighlight lang="bash">
$HOME/playground/bin/krep
$HOME/playground/share/apps/krep
$HOME/playground/share/icons/hicolor/22x22/apps/krep.png
</syntaxhighlight>
 
With this method you can easy see what you will get.
 
{{Note| You can still not see the icon in your application because $HOME/playground is not a know path by kde.
Normaly kde support a user defined space under $HOME/.kde.
 
Find out if this is supported with the command
<syntaxhighlight lang="bash">
kde4-config -path icon
</syntaxhighlight>


using this test case I could remove one icon after the other, 22x22, 64x64, 48x48, but when I removed 32x32, the icon disappeared from my application. This was the last icon that existed. Then I put in the 64x64 icon and the application carried an icon again. This means you can use any icon of 16x16, 22x22, 32x32, 48x48, 64x64, 128x128.
finally you have to extend the search path for kde
<syntaxhighlight lang="bash">
export KDEDIRS=$KDEDIRS:$HOME/playground
</syntaxhighlight>
}}


= The icon naming scheme =
= The icon naming scheme =
Example for icon names:
Example for icon names:
* hisc-apps-bla.svgz will be installed e.g. to /usr/local/share/icons/hicolor/scalable/apps/./bla.svgz. hi stands for "hicolor", sc for "scalable", apps for "applications", bla for the application's name and .svgz is the suffix for gzipped scalable vector graphic files.
* hisc-apps-bla.svgz will be installed e.g. to /usr/local/share/icons/hicolor/scalable/apps/bla.svgz. <tt>hi</tt> stands for "hicolor", <tt>sc</tt> for "scalable", <tt>apps</tt> for "applications", <tt>bla</tt> for the application's name and <tt>.svgz</tt> is the suffix for gzipped scalable vector graphic files.
* hi128-app-ktimetracker.png will be installed e.g. to /usr/share/icons/hicolor/128x128/apps/ktimetracker.png. hi stands for "hicolor", 128 for a resolution of 128x128 pixels, app for "applications", ktimetracker for the application's name and .png is the suffix for portable network graphic files.
* hi128-apps-ktimetracker.png will be installed e.g. to /usr/share/icons/hicolor/128x128/apps/ktimetracker.png. <tt>hi</tt> stands for "hicolor", <tt>128</tt> for a resolution of 128x128 pixels, <tt>apps</tt> for "applications", <tt>ktimetracker</tt> for the application's name and <tt>.png</tt> is the suffix for portable network graphic files.


= example application =
= example application =
You can obtain an example application ''kicons'' as part of kdeexamples by calling
In this chapter we will build - on top of the [[Development/Tutorials/Using_KActions|KAction example]] - an example application ''kicons'' that looks like this:
 
[[File:Snapshot-tutorial-kicon.png]]
 
You can obtain its source code as part of kdeexamples by calling
  git clone git://anongit.kde.org/kdeexamples
  git clone git://anongit.kde.org/kdeexamples


Line 60: Line 95:
The example application consists of  
The example application consists of  
* [http://quickgit.kde.org/?p=kdeexamples.git&a=blob&f=kicons/main.cpp main.cpp]
* [http://quickgit.kde.org/?p=kdeexamples.git&a=blob&f=kicons/main.cpp main.cpp]
: just taken from the [[Development/Tutorials/Using_KActions|KAction example]]
* [http://quickgit.kde.org/?p=kdeexamples.git&a=blob&f=kicons/mainwindow.cpp mainwindow.cpp]
* [http://quickgit.kde.org/?p=kdeexamples.git&a=blob&f=kicons/mainwindow.cpp mainwindow.cpp]
: Note the command <syntaxhighlight lang="bash">clearAction->setIcon(KIcon("tutorial-kicon"));</syntaxhighlight> that sets the icon
* [http://quickgit.kde.org/?p=kdeexamples.git&a=blob&f=kicons/mainwindow.h mainwindow.h]
* [http://quickgit.kde.org/?p=kdeexamples.git&a=blob&f=kicons/mainwindow.h mainwindow.h]
: just taken from the [[Development/Tutorials/Using_KActions|KAction example]]
* [http://quickgit.kde.org/?p=kdeexamples.git&a=blob&f=kicons/world.svg world.svg]
* [http://quickgit.kde.org/?p=kdeexamples.git&a=blob&f=kicons/world.svg world.svg]
: This is a file that defines our icon in (almost natural) english language. It is a scalable vector graphic file. Before being used, it must be converted into a zipped scalable vector graphic named ''hisc-apps-tutorial-kicon.svgz'', see below.
* [http://quickgit.kde.org/?p=kdeexamples.git&a=blob&f=kicons/tutorial-kiconui.rc tutorial-kiconui.rc]
* [http://quickgit.kde.org/?p=kdeexamples.git&a=blob&f=kicons/tutorial-kiconui.rc tutorial-kiconui.rc]
: just taken from the [[Development/Tutorials/Using_KActions|KAction example]]
* [http://quickgit.kde.org/?p=kdeexamples.git&a=blob&f=kicons/hisc-apps-tutorial-kicon.svgz hisc-apps-tutorial-kicon.svgz]
* [http://quickgit.kde.org/?p=kdeexamples.git&a=blob&f=kicons/hisc-apps-tutorial-kicon.svgz hisc-apps-tutorial-kicon.svgz]
: sorry for the name, but there are [[#The_icon_naming_scheme|naming conventions]]. Create this file with the command convert from the ImageMagick package <code>convert world.svg hisc-apps-tutorial-kicon.svgz</code>
: sorry for the name, but there are [[#The_icon_naming_scheme|naming conventions]]. Create this file with the ''convert'' command from the ''ImageMagick'' package <syntaxhighlight lang="bash">convert world.svg hisc-apps-tutorial-kicon.svgz</syntaxhighlight>
* [http://quickgit.kde.org/?p=kdeexamples.git&a=blob&f=kicons/CMakeLists.txt CMakeLists.txt]
* [http://quickgit.kde.org/?p=kdeexamples.git&a=blob&f=kicons/CMakeLists.txt CMakeLists.txt]
: Note the commands <syntaxhighlight lang="bash">kde4_install_icons(${ICON_INSTALL_DIR})</syntaxhighlight> and <syntaxhighlight lang="bash">kde4_update_iconcache()</syntaxhighlight> which integrate the icons.


== build it ==
== build it ==
To compile, link and install the example application, do a
To compile, link and install the example application, do a
cmake . && make && make install
<syntaxhighlight lang="bash">
mkdir build && cd build
cmake ../ && make && make install
</syntaxhighlight>
To run it, call
To run it, call
tutorial-kicon
<syntaxhighlight lang="bash">
tutorial-kicon
</syntaxhighlight>


= Analyzing the KApplications =
= Analyzing the KApplications =
Maybe you have already searched for yourself how a KDE application finds its icons. You will not be successful like this:
Maybe you have already searched for yourself how a KDE application finds its icons. You will not be successful like this:
<syntaxhighlight lang="bash">
  # [http://www.linuxintro.org/wiki/Strace#Search_for_a_syscall strace -e open] ktimetracker 2>&1 | grep icon
  # [http://www.linuxintro.org/wiki/Strace#Search_for_a_syscall strace -e open] ktimetracker 2>&1 | grep icon
  open("/usr/lib64/libkemoticons.so.4", O_RDONLY) = 3
  open("/usr/lib64/libkemoticons.so.4", O_RDONLY) = 3
  #
  #
</syntaxhighlight>
You see, a KDE application (in this case ktimetracker) does not open icon files or even look for them. However, it spawns a process to look for these icons:
You see, a KDE application (in this case ktimetracker) does not open icon files or even look for them. However, it spawns a process to look for these icons:
 
<syntaxhighlight lang="bash">
  linux-qgla:~/repos/kdepim/ktimetracker # strace -ffe open ktimetracker 2>&1 | grep icon
  linux-qgla:~/repos/kdepim/ktimetracker # strace -ffe open ktimetracker 2>&1 | grep icon
  open("/usr/lib64/libkemoticons.so.4", O_RDONLY) = 3
  open("/usr/lib64/libkemoticons.so.4", O_RDONLY) = 3
Line 90: Line 138:
  [pid  3457] open("/var/tmp/kdecache-root/kpc/kde-icon-cache.index", O_RDONLY|O_CLOEXEC) = 10
  [pid  3457] open("/var/tmp/kdecache-root/kpc/kde-icon-cache.index", O_RDONLY|O_CLOEXEC) = 10
  [...]
  [...]
</syntaxhighlight>
= Moving On =
Now you can move on to [[Development/Tutorials/Desktop_File|how to place your application in the K-Menu using .desktop files]].


= See also =
[[Category:C++]]
* [[Development/Tutorials]]

Latest revision as of 22:47, 29 May 2019

Warning
This page needs a review and probably holds information that needs to be fixed.

Parts to be reviewed:

Port to KF5

When you create your own KDE application you will probably want icons in it like this:

These icons are called KIcons. This article shows you how to do this using the software krep as an example. In case of a CMake-based project you will need to

How to use icons in QMake-based projects is discussed elsewhere.

Your KDE project

If you have a KDE project and want to use icons within it, and want these icons installed seamlessly, you will have to name the icons after the project. In the following we look at a project named krep. The important lines in CMakeLists.txt are the ones printed bold below:

PROJECT( krep )
FIND_PACKAGE( KDE4 REQUIRED )
INCLUDE_DIRECTORIES( ${KDE4_INCLUDES} . )
 
SET( krepSources main.cpp krep.cpp krep.h )
 
qt4_add_dbus_adaptor( krepSources 
                      org.kde.krep.xml
                      krep.h
                      krep
                      mainadaptor
                      MainAdaptor )
 
kde4_add_ui_files( krepSources krepui.ui )
 
kde4_add_app_icon( krepSources "hi*-app-krep.png" )
 
KDE4_ADD_EXECUTABLE( krep ${krepSources} )
 
TARGET_LINK_LIBRARIES( krep ${KDE4_KPARTS_LIBS} )
 
install( TARGETS krep ${INSTALL_TARGETS_DEFAULT_ARGS} )
 
kde4_install_icons( ${ICON_INSTALL_DIR} )

Weitere Informationen:

How to test it

The easy way is to define a custom cmake install prefix where you can simply insall the project without touching your system. Use following commands to setup this:

cd build
cmake -DCMAKE_INSTALL_PREFIX=$HOME/playground ../
make && make install

now the files should be deployed under

$HOME/playground/bin/krep
$HOME/playground/share/apps/krep
$HOME/playground/share/icons/hicolor/22x22/apps/krep.png

With this method you can easy see what you will get.

Note
You can still not see the icon in your application because $HOME/playground is not a know path by kde.

Normaly kde support a user defined space under $HOME/.kde.

Find out if this is supported with the command

kde4-config -path icon

finally you have to extend the search path for kde

export KDEDIRS=$KDEDIRS:$HOME/playground


The icon naming scheme

Example for icon names:

  • hisc-apps-bla.svgz will be installed e.g. to /usr/local/share/icons/hicolor/scalable/apps/bla.svgz. hi stands for "hicolor", sc for "scalable", apps for "applications", bla for the application's name and .svgz is the suffix for gzipped scalable vector graphic files.
  • hi128-apps-ktimetracker.png will be installed e.g. to /usr/share/icons/hicolor/128x128/apps/ktimetracker.png. hi stands for "hicolor", 128 for a resolution of 128x128 pixels, apps for "applications", ktimetracker for the application's name and .png is the suffix for portable network graphic files.

example application

In this chapter we will build - on top of the KAction example - an example application kicons that looks like this:

You can obtain its source code as part of kdeexamples by calling

git clone git://anongit.kde.org/kdeexamples

files

The example application consists of

just taken from the KAction example
Note the command
clearAction->setIcon(KIcon("tutorial-kicon"));
that sets the icon
just taken from the KAction example
This is a file that defines our icon in (almost natural) english language. It is a scalable vector graphic file. Before being used, it must be converted into a zipped scalable vector graphic named hisc-apps-tutorial-kicon.svgz, see below.
just taken from the KAction example
sorry for the name, but there are naming conventions. Create this file with the convert command from the ImageMagick package
convert world.svg hisc-apps-tutorial-kicon.svgz
Note the commands
kde4_install_icons(${ICON_INSTALL_DIR})
and
kde4_update_iconcache()
which integrate the icons.

build it

To compile, link and install the example application, do a

mkdir build && cd build
cmake ../ && make && make install

To run it, call

tutorial-kicon

Analyzing the KApplications

Maybe you have already searched for yourself how a KDE application finds its icons. You will not be successful like this:

 # [http://www.linuxintro.org/wiki/Strace#Search_for_a_syscall strace -e open] ktimetracker 2>&1 | grep icon
 open("/usr/lib64/libkemoticons.so.4", O_RDONLY) = 3
 #

You see, a KDE application (in this case ktimetracker) does not open icon files or even look for them. However, it spawns a process to look for these icons:

 linux-qgla:~/repos/kdepim/ktimetracker # strace -ffe open ktimetracker 2>&1 | grep icon
 open("/usr/lib64/libkemoticons.so.4", O_RDONLY) = 3
 [pid  3457] open("/root/.icons/DMZ/cursors/left_ptr", O_RDONLY) = -1 ENOENT (No such file or directory)
 [pid  3457] open("/root/.icons/DMZ/index.theme", O_RDONLY) = -1 ENOENT (No such file or directory)
 [pid  3457] open("/usr/share/icons/DMZ/cursors/left_ptr", O_RDONLY) = 10
 [pid  3457] open("/var/tmp/kdecache-root/icon-cache.kcache", O_RDWR|O_CREAT|O_CLOEXEC, 0666) = 10
 [pid  3457] open("/var/tmp/kdecache-root/kpc/kde-icon-cache.data", O_RDONLY|O_CLOEXEC) = 10
 [pid  3457] open("/var/tmp/kdecache-root/kpc/kde-icon-cache.index", O_RDONLY|O_CLOEXEC) = 10
 [...]

Moving On

Now you can move on to how to place your application in the K-Menu using .desktop files.