Aqt.Cassowary (pronounced like Acute Cassowary) is a Qt plugin that allows you to run a incremental linear constraint solver in QML applications, providing a declarative interface that fits naturally in the QML programming model.

It is a wrapper around Rhea, which is modern C++ implementation based on the original Cassowary linear constraint solver.

Incremental linear constraint what the heck...?

A linear constraint solver allows you to specify the relationship between variables (constraints) without necessarily giving them specific values. The system can then automatically find values for these variables that satisfy all the specified relationships. It is incremental, because the constraints can change and the system reuses previous solutions to provide stable results fast.

Cassowary is most useful for writing layout code for responsive applications with very dynamic content. It is the tool you need when anchors or QtQuick.Layouts are too rigid for you. Check the examples in examples for more details.

Status

The library is currently under heavy active development. The API is not stable yet. Use at your own risk.

Documentation

Reference documentation can be browsed here. It can be generated by executing in the project directory: doxygen doc/doxygen.config.

You can also check the examples in here.

Requirements

Dependencies:

Test dependencies:

Build and Test

  mkdir build
  cd build
  cmake ..
  cmake --build .

The unit tests can be executed with ctest:

  ctest -V

You might set the following variables:

In case the CMake files shipped with Qt are not found, set the CMAKE_PREFIX_PATH to the Qt installation prefix. See the Qt5 CMake manual for more.

Example:

  cmake .. -DCMAKE_PREFIX_PATH=~/Qt/Qt5.3.1/clang_64 \
           -DBoost_INCLUDE_DIR=/opt/local/include/

License

Aqt.Casssowary is distributed under the MIT license (see LICENSE).

Copyright (c) 2014, 2015 Ableton AG, Berlin

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.