/*
* Copyright (c) 2009-2012 jMonkeyEngine
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* * Neither the name of 'jMonkeyEngine' nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package com.jme3.app.state;
import com.jme3.app.Application;
import com.jme3.renderer.RenderManager;
/**
* AppState represents continously executing code inside the main loop.
*
* An <code>AppState</code> can track when it is attached to the
* {@link AppStateManager} or when it is detached.
*
* <br/><code>AppState</code>s are initialized in the render thread, upon a call to
* {@link AppState#initialize(com.jme3.app.state.AppStateManager, com.jme3.app.Application) }
* and are de-initialized upon a call to {@link AppState#cleanup()}.
* Implementations should return the correct value with a call to
* {@link AppState#isInitialized() } as specified above.<br/>
*
* <ul>
* <li>If a detached AppState is attached then <code>initialize()</code> will be called
* on the following render pass.
* </li>
* <li>If an attached AppState is detached then <code>cleanup()</code> will be called
* on the following render pass.
* </li>
* <li>If you attach an already-attached <code>AppState</code> then the second attach
* is a no-op and will return false.
* </li>
* <li>If you both attach and detach an <code>AppState</code> within one frame then
* neither <code>initialize()</code> or <code>cleanup()</code> will be called,
* although if either is called both will be.
* </li>
* <li>If you both detach and then re-attach an <code>AppState</code> within one frame
* then on the next update pass its <code>cleanup()</code> and <code>initialize()</code>
* methods will be called in that order.
* </li>
* </ul>
* @author Kirill Vainer
*/
public interface AppState {
/**
* Called by {@link AppStateManager} when transitioning this {@code AppState}
* from <i>initializing</i> to <i>running</i>.<br>
* This will happen on the next iteration through the update loop after
* {@link AppStateManager#attach(com.jme3.app.state.AppState) } was called.
* <p>
* <code>AppStateManager</code> will call this only from the update loop
* inside the rendering thread. This means is it safe to modify the scene
* graph from this method.
*
* @param stateManager The state manager
* @param app The application
*/
public void initialize(AppStateManager stateManager, Application app);
/**
* @return True if <code>initialize()</code> was called on the state,
* false otherwise.
*/
public boolean isInitialized();
/**
* Enable or disable the functionality of the <code>AppState</code>.
* The effect of this call depends on implementation. An
* <code>AppState</code> starts as being enabled by default.
* A disabled <code>AppState</code>s does not get calls to
* {@link #update(float)}, {@link #render(RenderManager)}, or
* {@link #postRender()} from its {@link AppStateManager}.
*
* @param active activate the AppState or not.
*/
public void setEnabled(boolean active);
/**
* @return True if the <code>AppState</code> is enabled, false otherwise.
*
* @see AppState#setEnabled(boolean)
*/
public boolean isEnabled();
/**
* Called by {@link AppStateManager#attach(com.jme3.app.state.AppState) }
* when transitioning this
* <code>AppState</code> from <i>detached</i> to <i>initializing</i>.
* <p>
* There is no assumption about the thread from which this function is
* called, therefore it is <b>unsafe</b> to modify the scene graph
* from this method. Please use
* {@link #initialize(com.jme3.app.state.AppStateManager, com.jme3.app.Application) }
* instead.
*
* @param stateManager State manager to which the state was attached to.
*/
public void stateAttached(AppStateManager stateManager);
/**
* Called by {@link AppStateManager#detach(com.jme3.app.state.AppState) }
* when transitioning this
* <code>AppState</code> from <i>running</i> to <i>terminating</i>.
* <p>
* There is no assumption about the thread from which this function is
* called, therefore it is <b>unsafe</b> to modify the scene graph
* from this method. Please use
* {@link #cleanup() }
* instead.
*
* @param stateManager The state manager from which the state was detached from.
*/
public void stateDetached(AppStateManager stateManager);
/**
* Called to update the <code>AppState</code>. This method will be called
* every render pass if the <code>AppState</code> is both attached and enabled.
*
* @param tpf Time since the last call to update(), in seconds.
*/
public void update(float tpf);
/**
* Render the state. This method will be called
* every render pass if the <code>AppState</code> is both attached and enabled.
*
* @param rm RenderManager
*/
public void render(RenderManager rm);
/**
* Called after all rendering commands are flushed. This method will be called
* every render pass if the <code>AppState</code> is both attached and enabled.
*/
public void postRender();
/**
* Called by {@link AppStateManager} when transitioning this
* <code>AppState</code> from <i>terminating</i> to <i>detached</i>. This
* method is called the following render pass after the <code>AppState</code> has
* been detached and is always called once and only once for each time
* <code>initialize()</code> is called. Either when the <code>AppState</code>
* is detached or when the application terminates (if it terminates normally).
*/
public void cleanup();
}