It's a straightforward binding, which uses JNI to do a direct calls to Dear ImGui API.
Since we live in Java world - some things require to do them respectively to that fact. Please read Binding notice. Despite this fact, see official documentation and wiki to get more info about how to do things in ImGui.

Binding doesn't force you to use backend renderer which is introduced here. Feel free to use your own render engine if you need so. See how things are done in ImGuiImplGl3.

Binding has the next version naming: imguiVersion-bindingVersion.
For example 1.74-0.1 means that binding uses 1.74 version of ImGui and binding itself has version 0.1.

Some of the very specific features are still in a wip state.

How to try

Make sure you have installed Java 8 or higher.

You can try this binding by yourself in a three simple steps:

git clone --branch v1.74-0.4.1 https://github.com/SpaiR/imgui-java.git
cd imgui-java
gradlew :imgui-lwjgl3:startExample

That's it! This will start an example app ImGuiGlfwExample which relies on GLFW and LWJGL3. Feel free to modify ImGuiGlfwExample#showUi method to try different ImGui widgets in action.

GIF with example

How to use

Step 1

Add jcenter repository:

repositories {
    jcenter()
}

Step 2

Add binding dependency:

implementation 'io.imgui.java:binding:1.74-0.4.1'

Step 3

If you want to use LWJGL3 renderer:

implementation 'io.imgui.java:lwjgl3:1.74-0.4.1'

Disclaimer!
LWJGL3 renderer is based on the 3.2.3 version of the LWJGL. You'll need to add additional dependencies to it. Specifically lwjgl itself, glfw and opengl modules. You can find how to do that here.

Step 4

Add binary lib dependency:

runtimeOnly "io.imgui.java:$imguiNatives:1.74-0.4.1"

Where imguiNatives could be:

natives-linux
natives-linux-x86
natives-windows
natives-windows-x86

(x86 suffix is to get 32bit library)

Or alternatively you can download binaries manually:
Go to the /bin folder and pick a native library for your OS. Then you'll need to provide imgui.library.path or java.library.path VM option with path to a folder where you placed downloaded file.

Result build.gradle could look like this

repositories {
    jcenter()
}

dependencies {
    implementation 'io.imgui.java:binding:1.74-0.4.1'
    implementation 'io.imgui.java:lwjgl3:1.74-0.4.1'
    runtimeOnly "io.imgui.java:natives-windows:1.74-0.4.1"
}

You are ready to use imgui-java binding!

Binding notice:

All ImGui methods are available in camelCase, not in PascalCase.
In places where in C++ you need to pass ImVec2 or ImVec4, here you'll need to pass two or four float parameters respectively.
When you need to get an input/output to/from the Dear-ImGui use primitive wrappers: ImBool, ImInt etc.
Due to the Java and JNI restrictions we can't provide a fully fledged callbacks to the ImGui::InputText*() methods. Partly you could replace some of the features (like setting of the allowed chars to input) by using the ImGuiInputTextData class. Read javadoc to get more info.

How to build

To build native libraries you should install mingw-w64 and ant. Modify GenerateLibs to build specific binaries you need. After everything is configure run gradlew :imgui-binding:generateLibs task. This will build native libraries and place them in ~/imgui-binding/build/libsNative folder.

Credits

This binding is partly based on the work of xpenatan and his version jDear-imgui.

License

See the LICENSE file for license rights and limitations (Apache-2.0).