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Writing a New View Module¶

Intro¶

This guide will use the LottieView class implementation as an example to demonstrate the steps needed to extend the Boden Framework with new standalone view module.

Boden views consist of two parts:

The outward facing platform-independent View class. This is what users of your view component will usually see and interact with.
The internal platform-specific View::Core implementation. This part of the view implementation is usually hidden from users of your new view component.

The Module Structure¶

A view module consists of the public part (mostly the View class), and a number of platform-specific implementations:

lottieview
├── include
│── src
├── platforms
│  ├── android
│  │  ├── include
│  │  ├── java
│  │  └── src
│  ├── ios
│  │  ├── include
│  │  └── src
│  └── mac
│     ├── include
│     └── src

Main CMakeLists.txt¶

Full CMakeLists.txt

add_sources(_BDN_LOTTIEVIEW_FILES _BDN_LOTTIEVIEW_HEADERS ./)
GenerateTopLevelIncludeFile(_BDN_LOTTIEVIEW_COMBINED
    ${CMAKE_CURRENT_BINARY_DIR}/include/bdn/lottieview-module.h
    ${CMAKE_CURRENT_LIST_DIR}/include
    ${_BDN_LOTTIEVIEW_HEADERS})
list(APPEND _BDN_LOTTIEVIEW_FILES
    ${_BDN_LOTTIEVIEW_COMBINED}
    ${_BDN_LOTTIEVIEW_HEADERS})
add_universal_library(lottieview TIDY SOURCES ${_BDN_LOTTIEVIEW_FILES})
target_link_libraries(lottieview PUBLIC foundation ui)
target_include_directories(lottieview
    PUBLIC
    $<INSTALL_INTERFACE:include>
    $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
    )
target_include_directories(lottieview PUBLIC
    $<BUILD_INTERFACE:${CMAKE_CURRENT_BINARY_DIR}/include>)
include(install.cmake)
add_subdirectory(platforms)
add_library(Boden::LottieView ALIAS lottieview)
target_link_libraries(Boden_All INTERFACE lottieview)

add_sources(_BDN_LOTTIEVIEW_FILES _BDN_LOTTIEVIEW_HEADERS ./)

add_sources gathers all files from the ./include and ./src folders.

GenerateTopLevelIncludeFile(_BDN_LOTTIEVIEW_COMBINED
    ${CMAKE_CURRENT_BINARY_DIR}/include/bdn/lottieview-module.h
    ${CMAKE_CURRENT_LIST_DIR}/include
    ${_BDN_LOTTIEVIEW_HEADERS})

GenerateTopLevelIncludeFile creates a convenience header file that includes all files from the ./include folder

list(APPEND _BDN_LOTTIEVIEW_FILES
    ${_BDN_LOTTIEVIEW_COMBINED}
    ${_BDN_LOTTIEVIEW_HEADERS})
add_universal_library(lottieview TIDY SOURCES ${_BDN_LOTTIEVIEW_FILES})

All files are then combined and the main library is created. The TIDY option includes the source files in clang-tidy runs.

target_link_libraries(lottieview PUBLIC Boden::UI)
target_include_directories(lottieview
    PUBLIC
    $<INSTALL_INTERFACE:include>
    $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
    )
target_include_directories(lottieview PUBLIC
    $<BUILD_INTERFACE:${CMAKE_CURRENT_BINARY_DIR}/include>)
include(install.cmake)

We link the library against the Boden::UI library. The include directories are specified here such that they work whether Boden is included in source form or as a bundled installation

Now you can write your view as described in Writing a New View.