GuiBlinkingImage.java

package hunternif.mc.atlas.client.gui.core;

import hunternif.mc.atlas.util.AtlasRenderHelper;
import net.minecraft.client.renderer.GlStateManager;
import net.minecraft.util.ResourceLocation;
import org.lwjgl.opengl.GL11;

/** Displays a texture that changes alpha at regular intervals.
 * By default the texture file is assumed to be full image, but that behavior
 * can be altered by overriding the method {@link #drawImage()}.
 * @author Hunternif
 */
public class GuiBlinkingImage extends GuiComponent {
	private ResourceLocation texture;
	/** The number of milliseconds the icon spends visible or invisible. */
	private long blinkTime = 500;
	private float visibleAlpha = 1;
	private float invisibleAlpha = 0.25f;
	
	private long lastTickTime;
	/** The flag that switches value every "blink". */
	private boolean isVisible;
	
	public void setTexture(ResourceLocation texture, int width, int height) {
		this.texture = texture;
		setSize(width, height);
		// Set up the timer so that the image appears visible at the first moment:
		lastTickTime = 0;
		isVisible = false;
	}
	
	/** The number of milliseconds the icon spends visible or invisible. */
	public void setBlinkTime(long blinkTime) {
		this.blinkTime = blinkTime;
	}

	public void setVisibleAlpha(float visibleAlpha) {
		this.visibleAlpha = visibleAlpha;
	}

	public void setInvisibleAlpha(float invisibleAlpha) {
		this.invisibleAlpha = invisibleAlpha;
	}
	
	@Override
	public void drawScreen(int mouseX, int mouseY, float partialTick) {
		long currentTime = System.currentTimeMillis();
		if (lastTickTime + blinkTime < currentTime) {
			lastTickTime = currentTime;
			isVisible = !isVisible;
		}
		GlStateManager.color(1, 1, 1, isVisible ? visibleAlpha : invisibleAlpha);
		GlStateManager.enableBlend();
		GlStateManager.blendFunc(GL11.GL_SRC_ALPHA, GL11.GL_ONE_MINUS_SRC_ALPHA);
		drawImage();
	}
	
	private void drawImage() {
		AtlasRenderHelper.drawFullTexture(texture, getGuiX(), getGuiY(), getWidth(), getHeight());
	}
}