name.martingeisse.stackd.client.gui.element.TextParagraph.java Source code

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Here is the source code for name.martingeisse.stackd.client.gui.element.TextParagraph.java

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/**
 * Copyright (c) 2010 Martin Geisse
 *
 * This file is distributed under the terms of the MIT license.
 */

package name.martingeisse.stackd.client.gui.element;

import static org.lwjgl.opengl.GL14.glWindowPos2i;
import java.util.ArrayList;
import name.martingeisse.common.util.ParameterUtil;
import name.martingeisse.stackd.client.gui.Gui;
import name.martingeisse.stackd.client.gui.GuiElement;
import name.martingeisse.stackd.client.gui.GuiEvent;
import name.martingeisse.stackd.client.gui.util.Color;
import name.martingeisse.stackd.client.system.Font;
import org.apache.commons.lang3.StringUtils;
import org.lwjgl.opengl.GL11;

/**
 * This element draws a paragraph of text, breaking the text into lines
 * of the width requested by the enclosing element.
 */
public final class TextParagraph extends GuiElement {

    /**
     * the NO_LINES
     */
    private static final String[] NO_LINES = new String[0];

    /**
     * the font
     */
    private Font font;

    /**
     * the color
     */
    private Color color;

    /**
     * the text
     */
    private String text;

    /**
     * the lines
     */
    private String[] lines;

    /**
     * Constructor.
     */
    public TextParagraph() {
        this.font = null;
        this.color = Color.WHITE;
        this.text = "";
        this.lines = NO_LINES;
    }

    /**
     * Getter method for the font.
     * @return the font
     */
    public Font getFont() {
        return font;
    }

    /**
     * Setter method for the font.
     * @param font the font to set
     * @return this for chaining
     */
    public TextParagraph setFont(final Font font) {
        ParameterUtil.ensureNotNull(font, "font");
        this.font = font;
        requestLayout();
        return this;
    }

    /**
     * Getter method for the color.
     * @return the color
     */
    public Color getColor() {
        return color;
    }

    /**
     * Setter method for the color.
     * @param color the color to set
     * @return this for chaining
     */
    public TextParagraph setColor(final Color color) {
        ParameterUtil.ensureNotNull(color, "color");
        this.color = color;
        return this;
    }

    /**
     * Getter method for the text.
     * @return the text
     */
    public String getText() {
        return text;
    }

    /**
     * Setter method for the text.
     * @param text the text to set
     * @return this for chaining
     */
    public TextParagraph setText(final String text) {
        ParameterUtil.ensureNotNull(text, "text");
        this.text = text;
        requestLayout();
        return this;
    }

    /**
     * 
     */
    private Font getEffectiveFont() {
        if (font == null) {
            final Gui gui = getGuiOrNull();
            return (gui == null ? null : gui.getDefaultFont());
        } else {
            return font;
        }
    }

    /* (non-Javadoc)
     * @see name.martingeisse.stackd.client.gui.GuiElement#finishLayoutSize(int, int)
     */
    @Override
    public void requestSize(final int width, final int height) {

        // obtain the font
        final Font effectiveFont = getEffectiveFont();
        if (effectiveFont == null || text == null) {
            setSize(0, 0);
            return;
        }

        // break the text into lines
        final Gui gui = getGui();
        ArrayList<String> lines = new ArrayList<>();
        StringBuilder lineBuilder = new StringBuilder();
        for (String word : StringUtils.split(text.trim())) {
            if (lineBuilder.length() != 0) {
                lineBuilder.append(' ');
            }
            int previousCharacterCount = lineBuilder.length();
            lineBuilder.append(word);
            int newSize = gui.pixelsToUnitsInt(effectiveFont.getStringWidth(lineBuilder.toString()));
            if (newSize > width) {
                lineBuilder.setLength(previousCharacterCount);
                lines.add(lineBuilder.toString());
                lineBuilder.setLength(0);
                lineBuilder.append(word);
            }
        }
        if (lineBuilder.length() > 0) {
            lines.add(lineBuilder.toString());
        }
        this.lines = lines.toArray(new String[lines.size()]);

        // determine the size of the paragraph
        final int lineHeight = gui.pixelsToUnitsInt(effectiveFont.getCharacterHeight());
        setSize(width, lineHeight * this.lines.length);

    }

    /* (non-Javadoc)
     * @see name.martingeisse.stackd.client.gui.GuiElement#handleEvent(name.martingeisse.stackd.client.gui.GuiEvent)
     */
    @Override
    public void handleEvent(final GuiEvent event) {
        if (event == GuiEvent.DRAW) {
            final Font effectiveFont = getEffectiveFont();
            GL11.glDisable(GL11.GL_TEXTURE_2D);
            GL11.glEnable(GL11.GL_BLEND);
            GL11.glBlendFunc(GL11.GL_SRC_ALPHA, GL11.GL_ONE_MINUS_SRC_ALPHA);
            GL11.glPixelTransferf(GL11.GL_RED_SCALE, 0.0f);
            GL11.glPixelTransferf(GL11.GL_GREEN_SCALE, 0.0f);
            GL11.glPixelTransferf(GL11.GL_BLUE_SCALE, 0.0f);
            GL11.glPixelTransferf(GL11.GL_ALPHA_SCALE, 1.0f);
            GL11.glPixelTransferf(GL11.GL_RED_BIAS, color.getRed() / 255.0f);
            GL11.glPixelTransferf(GL11.GL_GREEN_BIAS, color.getGreen() / 255.0f);
            GL11.glPixelTransferf(GL11.GL_BLUE_BIAS, color.getBlue() / 255.0f);
            GL11.glPixelTransferf(GL11.GL_ALPHA_BIAS, 0.0f);

            // TODO scale font so text doesn't become smaller with higher resolution
            final Gui gui = getGui();
            final int x = gui.unitsToPixelsInt(getAbsoluteX());
            final int y = getGui().getHeightPixels() - gui.unitsToPixelsInt(getAbsoluteY());

            final int lineHeight = effectiveFont.getCharacterHeight();
            int i = 0;
            for (String line : lines) {
                glWindowPos2i(x, y - i * lineHeight);
                effectiveFont.drawText(line, 1.0f, Font.ALIGN_LEFT, Font.ALIGN_TOP);
                i++;
            }

        }
    }

}