Qt API | Qtopia API | Qtopia Documentation |

## Qtopia - Getting Started

### Qtopia - The Qt palmtop environment

Qtopia is a windowing system for handheld devices. It offers developers the powerful Qt API, and provides users with fast and intuitive interaction.

#### Developing for Qtopia

Since Qtopia offers the complete Qt API, you can do much of your development on any of the other platforms for which Qt is available: Windows, Unix/X11, or Mac OS X. However, for optimal tailoring of your application to the smaller screen and other limitations of a small device, we recommend that you use the Qtopia SDK.

The Qtopia SDK allows you to develop Qtopia applications under the Linux desktop environment using the Qt Virtual Framebuffer, which completely emulates the handheld Qtopia environment. It also includes cross-compiler software so that you can compile your application to run on the target device. If you do not already have the Qtopia SDK (this document is normally part of the SDK), contact info@trolltech.com, or see the Trolltech web site.

To build applications for the SHARP SL5000 or similar StrongARM-based devices, you will also need a StrongARM cross compiler.

The SDK includes an example application. We recommend that you compile and run this example to learn how things work, before tackling your own projects.

Here are the steps necessary to compile and run the example program on the Linux desktop:

1. Check the environment is correct:

          export QPEDIR=/opt/Qtopia
          export QTDIR=/opt/Qtopia
          export PATH=$QTDIR/bin:$PATH
          export TMAKEPATH=/opt/Qtopia/tmake/lib/qws/linux-generic-g++
          export LD_LIBRARY_PATH=$QTDIR/lib:$LD_LIBRARY_PATH

2. Make a copy of the example:

          cd somewhere
          cp -r $QPEDIR/examples/application .
          cd application

3. Generate a Makefile:

          tmake -o Makefile example.pro

4. Build the example:

          make

5. Install it:

          su # root privileges required to install
          cp example.desktop $QPEDIR/apps/Applications/
          cp Example.png $QPEDIR/pics/
          cp example $QPEDIR/bin/
          cp example.html $QPEDIR/help/html/
          exit # no need to be root anymore

6. To run it, first run the Qt Virtual Framebuffer:

          qvfb &

7. Then run the Qtopia environment:

          qpe

   Your application should be available in the Applications tab visible inside the Qt Virtual Framebuffer window.

8. If you want to distribute your applications to others, build an RPM package, e.g.:

          mkipks -rpm -arch i386 example.control

To make your own application, use the example program as a model. Make sure that when you add files to your project, you also add them to your project file (i.e. to `example.pro`) and rerun the `tmake` command to update the `Makefile` whenever you update the `.pro` file.

To build you application for the SHARP SL5000 rather than just running on the desktop, the process is similar. The example below assumes you have installed the cross compiler in /usr/local/arm.

1. Check the environment is correctly set for the SHARP SL5000:

          export QPEDIR=/opt/Qtopia/sharp
          export QTDIR=/opt/Qtopia/sharp
          export PATH=$QTDIR/bin:/usr/local/arm/bin:$PATH
          export TMAKEPATH=/opt/Qtopia/tmake/lib/qws/linux-sharp-g++

2. Rebuild the makefile (`$TMAKEPATH` has changed) above:

          make clean
          tmake -o Makefile example.pro

3. Build it:

          make

4. Install it (note that this is now going into the `/opt/Qtopia/sharp/` directory):

          su # root privileges required to install
          cp example.desktop $QPEDIR/apps/Applications
          cp Example.png $QPEDIR/pics
          cp example $QPEDIR/bin
          cp example.html $QPEDIR/help/html/
          exit # no need to be root anymore

5. To install it on a device, build an `ipk` package file:

          su -m # root privileges required to strip the executable
          mkipks example.control
          exit # no need to be root anymore

The resulting `example-1.0.0.ipk` can be installed on the SL5000 using Qtopia Desktop.

#### Building Your Own Applications

Once you have built the example, you can proceed with writing your own applicatons. If you are not familiar with Qt, you should consult the Qt documentation by pointing your web browser at /opt/Qtopia/doc/index.html when you have installed the SDK, or use the online Trolltech Documentation Site. The Qt Whitepaper provides a good overview of, and introduction to, the Qt API.

When you add more files to your application, just edit the project file (e.g. `example.pro`) and rerun `tmake`.

The `.ui` files are Qt Designer user interface files. You can create and edit these using Qt Designer:

       designer example.ui

Qt Designer's online documentation (accessible from the links mentioned above) includes a complete tutorial.