imgui.app

Class Application

java.lang.Object

imgui.app.Window

imgui.app.Application

public abstract class Application
extends Window

Application class from which ImGui applications extend. Serves as an abstraction layer to hide all low-level details about window creation and rendering routine.

Life-cycle

The entry point for ImGui applications is the Application class and launch(Application) method. It initializes application instance and starts the main application loop.

1. configure(Configuration) It's called before window creation, so only basic application setups are expected.
2. Window.initWindow(Configuration) Method creates application window.
3. Window.initImGui(Configuration) Method initializes Dear ImGui context. Could be used to do Dear ImGui setup as well.
4. preRun() Method called once, before application loop.
5. Window.preProcess() Method called every frame, before Window.process().
6. Window.process() Method is meant to be overridden with user application logic.
7. Window.postProcess() Method called every frame, after Window.process().
8. postRun() Method called once, after application loop.
9. Window.disposeImGui() Destroys Dear ImGui context.
10. Window.disposeWindow() Destroys application window.

As it could be seen, ImGui application differs from the classic one in the way of its life-cycle flow. Instead of creating widgets and adding listeners to them we have an application loop where everything is handled right away. Read more about Immediate GUI mode to understand that paradigm better.

Example

The simplest application example could be done in the next way:

 import imgui.ImGui;
 import imgui.app.Application;

 public class Main extends Application {
      @Override
     public void process() {
         ImGui.text("Hello, World!");
     }

     public static void main(final String[] args) {
         launch(new Main());
     }
 }
 

As its said, Window.process() method is meant to be overridden. All your application logic should go there.

Threading

Unlike other Java applications, ImGui is about "one thread for everything". You still can use multi-threading, but be careful. For example, large list of computations could be separated between application ticks. Window.process() method is called constantly. Use that wisely and remember that all GUI should be in the main thread.

Field Summary

Fields inherited from class imgui.app.Window

colorBg, handle

Constructor Summary

Constructors

Constructor and Description
Application()

Method Summary

Modifier and Type	Method and Description
protected void	configure(Configuration config) Method called before window creation.
static void	launch(Application app) Entry point of any ImGui application.
protected void	postRun() Method called once, after application run loop.
protected void	preRun() Method called once, before application run loop.

Methods inherited from class imgui.app.Window

dispose, disposeImGui, disposeWindow, endFrame, getColorBg, getHandle, init, initImGui, initWindow, postProcess, preProcess, process, run, startFrame

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Application

public Application()

Method Detail

configure

protected void configure(Configuration config)

Method called before window creation. Could be used to provide basic window information, like title name etc.

Parameters:

config - configuration object with basic window information

preRun

protected void preRun()

Method called once, before application run loop.

postRun

protected void postRun()

Method called once, after application run loop.

launch

public static void launch(Application app)

Entry point of any ImGui application. Use it to start the application loop.

Parameters:

app - application instance to run