An open source multi-platform app for digital signage
- Introduction
- Status
- Screenshots
- Build and run
- Display file structure
- Admin server
- Android intents
- Android TV launcher
- Built with
- License
The Displayer app shows your content, described in a JSON file, in an endless loop, without any intervention, on the device of your choice.
Some of its features are:
- Works on multiple platforms:
- Android, including Android TV
- Linux
- Any other platform supported by Kotlin Multiplatform (KMP)
- Multiple regions
- Center region to show your main content
- Left and Bottom region to show secondary (scrolling) content
- Different types of content:
- Text
- Images
- Clock
- Live weather information (requires an OpenWeather API key)
- Random content
- Locale-aware (for time formatting, temperature units,...)
- Is a launcher on Android platforms (including Android TV)
Displayer is being used successfully in the clubhouse of korfbalclub KCBJ to display information about upcoming events, sponsors, and live weather, without any intervention of the volunteer currently doing bar service.
This project is currently under heavy development and should be considered alpha-quality at best.
There are currently no binary builds available. You have to download/clone the source code and build the app to run it.
Building Displayer requires at minimum Java 17.
Optionally, you can open the project in IntelliJ IDEA (tested with version 2023.3.3 of the Community Edition running on Java 17)
- Define
sdk.dirinlocal.propertiesto point to your Android SDK location - Execute
./gradlew assembleto build the Android app - The resulting APK files will be placed in
android/build/outputs/apk - Use ADB to install the app on your Android device:
adb install android/build/outputs/apk/debug/android-debug.apk
- Execute
./gradlew packageto build the desktop apps - The resulting binaries will be placed in
desktop/build/compose/binaries
There are sample display files available showcasing different features.
A detailed explanation of the display file structure is coming soon...
Displayer has a built-in webserver that can be used to send commands and control the app from a remote device.
This server accepts commands sent via curl, wget or any web browser.
The admin server is not enabled by default.
On Android, you'll need ADB to start the admin server with the following command:
adb shell am start -a com.displayer.action.CONFIG -e com.displayer.extra.ADMIN_PORT YOUR_PORT -e com.displayer.extra.ADMIN_SECRET YOUR_SECRET
Replace YOUR_PORT with the TCP/IP port number to use for the admin server.
Replace YOUR_SECRET with a secret that must be included in any request to the admin port.
On desktop, you must start Displayer with extra parameters to enable the admin server.
Example:
/opt/displayer/bin/Displayer --admin-port=YOUR_PORT --admin-secret=YOUR_SECRET
Replace YOUR_PORT with the TCP/IP port number to use for the admin server.
Replace YOUR_SECRET with a secret that must be included in any request to the admin port.
curl "http://YOUR_HOST:YOUR_PORT/admin?secret=YOUR_SECRET&url=URL_OF_DISPLAY_FILE"
Replace URL_OF_DISPLAY_FILE with the URL of your own display file, e.g. https://example.com/displayer.json. Make sure you URL-encode all special characters in the URL.
curl -F 'data=@PATH_OF_DISPLAY_FILE' "http://YOUR_HOST:YOUR_PORT/admin/display?secret=YOUR_SECRET"
Replace PATH_OF_DISPLAY_FILE with the path of a local display file that will be uploaded.
curl "http://YOUR_HOST:YOUR_PORT/admin?secret=YOUR_SECRET&open-weather-api-key=YOUR_API_KEY"
Replace YOUR_API_KEY with your own OpenWeather API key obtained from the OpenWeather API console.
curl "http://YOUR_HOST:YOUR_PORT/admin?secret=YOUR_SECRET&kill-server"
The Android app also accepts a number of intents with extras.
You can use ADB to launch these intents.
adb shell am start -a android.intent.action.VIEW -d "URL_OF_DISPLAY_FILE"
Replace URL_OF_DISPLAY_FILE with the URL of your own display file, e.g. https://example.com/displayer.json
adb shell am start -a com.displayer.action.CONFIG -e EXTRA_OPEN_WEATHER_API_KEY YOUR_API_KEY
Replace YOUR_API_KEY with your own OpenWeather API key obtained from the OpenWeather API console.
adb shell am start -a com.displayer.action.KILL_SERVER
After installing Displayer on Android TV, you can disable the original Android TV launcher. This will make sure that Displayer automatically starts after rebooting your Android TV device.
To disable the original Android TV launcher enter the following commands:
adb shell pm disable-user --user 0 com.google.android.tvlauncher
adb shell pm disable-user --user 0 com.google.android.tungsten.setupwraith
You can always re-enable the original Android TV launcher by entering the following commands:
adb shell pm enable com.google.android.tvlauncher
adb shell pm enable com.google.android.tungsten.setupwraith
- Kotlin Multiplatform
- Compose Desktop
- Kotlin Serialization
- Kotlin Date/Time
- Ktor: HTTP server
- Koin: dependency injection framework
- Kamel: asynchronous media loading library for Compose
- Multiplatform settings: Kotlin Multiplatform library to persist key-value data
- Kermit: Kotlin Multiplatform logging
Copyright 2022 Norio BV
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.