test/jdk/java/awt/font/TextLayout/TestJustification.java

/*
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 *
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 * version 2 for more details (a copy is included in the LICENSE file that
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import java.awt.Color;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.Frame;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Insets;
import java.awt.Panel;
import java.awt.Rectangle;
import java.awt.Shape;
import java.awt.font.FontRenderContext;
import java.awt.font.LineBreakMeasurer;
import java.awt.font.TextAttribute;
import java.awt.font.TextLayout;
import java.awt.geom.Rectangle2D;
import java.text.AttributedCharacterIterator;
import java.text.AttributedString;

/*
 * @test
 * @bug 4211728 4178140 8145542
 * @summary Justify several lines of text and verify that the lines are the same
   length and cursor positions are correct.
   Bug 4211728: TextLayout.draw() draws characters at wrong position.
   Bug 4178140: TextLayout does not justify.
 * @library /java/awt/regtesthelpers
 * @build PassFailJFrame
 * @run main/manual TestJustification
 */

public class TestJustification {
    private static final String INSTRUCTIONS = """
            Five lines of text should appear, all justified to the same width,
            followed by a sixth line containing only roman characters and
            no spaces which is not justified, and instead is centered.
            Carets should appear between all characters.

            PASS the test if this is true, else press FAIL.
            """;

    public static void main(String[] args) throws Exception {

        PassFailJFrame.builder()
                      .title("Test Instructions")
                      .instructions(INSTRUCTIONS)
                      .rows((int) INSTRUCTIONS.lines().count() + 2)
                      .columns(35)
                      .testUI(TestJustification::createUI)
                      .build()
                      .awaitAndCheck();
    }

    private static Frame createUI() {
        Frame frame= new Frame("Test Text Justification");
        JustificationPanel panel = new JustificationPanel("Bitstream Cyberbit");
        frame.add(panel);
        frame.add("Center", panel);
        frame.setSize(500, 450);
        return frame;
    }

    static class JustificationPanel extends Panel {
        TextLayout[] layouts;
        String fontname;
        float height;
        float oldfsize;

        AttributedCharacterIterator lineText;
        TextLayout[] lines;
        int linecount;
        float oldwidth;

        JustificationPanel(String fontname) {
            this.fontname = fontname;
        }

        private static final String[] texts = {
                "This is an english Highlighting demo.", "Highlighting",
                "This is an arabic \u0627\u0628\u062a\u062c \u062e\u0644\u0627\u062e demo.", "arabic \u0627\u0628\u062a\u062c",
                "This is a hebrew \u05d0\u05d1\u05d2 \u05d3\u05d4\u05d5 demo.", "hebrew \u05d0\u05d1\u05d2",
                "This is a cjk \u4e00\u4e01\u4e02\uac00\uac01\uc4fa\uf900\uf901\uf902 demo.", "cjk",
                "NoSpaceCJK:\u4e00\u4e01\u4e02and\uac00\uac01\uc4faand\uf900\uf901\uf902", "No",
                "NoSpaceRoman", "Space"
        };

        public void paint(Graphics g) {
            Graphics2D g2d = (Graphics2D)g;

            Dimension d = getSize();
            Insets insets = getInsets();

            float w = d.width - insets.left - insets.right;
            float h = d.height - insets.top - insets.bottom;
            int fsize = (int)w/25;

            FontRenderContext frc = g2d.getFontRenderContext();

            if (layouts == null || fsize != oldfsize) {
                oldfsize = fsize;

                Font f0 = new Font(fontname, Font.PLAIN, fsize);
                Font f1 = new Font(fontname, Font.ITALIC, (int)(fsize * 1.5));

                if (layouts == null) {
                    layouts = new TextLayout[texts.length / 2];
                }

                height = 0;
                for (int i = 0; i < layouts.length; ++i) {
                    String text = texts[i*2];
                    String target = texts[i*2+1];

                    AttributedString astr = new AttributedString(text);
                    astr.addAttribute(TextAttribute.FONT, f0, 0, text.length());

                    int start = text.indexOf(target);
                    int limit = start + target.length();
                    astr.addAttribute(TextAttribute.FONT, f1, start, limit);

                    TextLayout layout = new TextLayout(astr.getIterator(), frc);

                    layout = layout.getJustifiedLayout(w - 20);

                    layouts[i] = layout;

                    height += layout.getAscent() + layout.getDescent() + layout.getLeading();
                }
            }

            g2d.setColor(Color.white);
            g2d.fill(new Rectangle.Float(insets.left, insets.top, w, h));

            float basey = 20;

            for (TextLayout layout : layouts) {
                float la = layout.getAscent();
                float ld = layout.getDescent();
                float ll = layout.getLeading();
                float lw = layout.getAdvance();
                float lh = la + ld + ll;
                float lx = (w - lw) / 2f;
                float ly = basey + layout.getAscent();

                g2d.setColor(Color.black);
                g2d.translate(insets.left + lx, insets.top + ly);

                Rectangle2D bounds = new Rectangle2D.Float(0, -la, lw, lh);
                g2d.draw(bounds);

                layout.draw(g2d, 0, 0);

                g2d.setColor(Color.red);
                for (int j = 0, e = layout.getCharacterCount(); j <= e; ++j) {
                    Shape[] carets = layout.getCaretShapes(j, bounds);
                    g2d.draw(carets[0]);
                }

                g2d.translate(-insets.left - lx, -insets.top - ly);
                basey += layout.getAscent() + layout.getDescent() + layout.getLeading();
            }

            // add LineBreakMeasurer-generated layouts

            if (lineText == null) {
                String text = "This is a long line of text that should be broken across multiple "
                              + "lines and then justified to fit the break width.  This test should pass if "
                              + "these lines are justified to the same width, and fail otherwise.  It should "
                              + "also format the hebrew (\u05d0\u05d1\u05d2 \u05d3\u05d4\u05d5) and arabic "
                              + "(\u0627\u0628\u062a\u062c \u062e\u0644\u0627\u062e) and CJK "
                              + "(\u4e00\u4e01\u4e02\uac00\uac01\uc4fa\u67b1\u67b2\u67b3\u67b4\u67b5\u67b6\u67b7"
                              + "\u67b8\u67b9) text correctly.";

                Float regular = 16.0F;
                Float big = 24.0F;
                AttributedString astr = new AttributedString(text);
                astr.addAttribute(TextAttribute.SIZE, regular, 0, text.length());
                astr.addAttribute(TextAttribute.FAMILY, fontname, 0, text.length());

                int ix = text.indexOf("broken");
                astr.addAttribute(TextAttribute.SIZE, big, ix, ix + 6);
                ix = text.indexOf("hebrew");
                astr.addAttribute(TextAttribute.SIZE, big, ix, ix + 6);
                ix = text.indexOf("arabic");
                astr.addAttribute(TextAttribute.SIZE, big, ix, ix + 6);
                ix = text.indexOf("CJK");
                astr.addAttribute(TextAttribute.SIZE, big, ix, ix + 3);

                lineText = astr.getIterator();
            }

            float width = w - 20;
            if (lines == null || width != oldwidth) {
                oldwidth = width;

                lines = new TextLayout[10];
                linecount = 0;

                LineBreakMeasurer measurer = new LineBreakMeasurer(lineText, frc);

                for (;;) {
                    TextLayout layout = measurer.nextLayout(width);
                    if (layout == null) {
                        break;
                    }

                    // justify all but last line
                    if (linecount > 0) {
                        lines[linecount - 1] = lines[linecount - 1].getJustifiedLayout(width);
                    }

                    if (linecount == lines.length) {
                        TextLayout[] nlines = new TextLayout[lines.length * 2];
                        System.arraycopy(lines, 0, nlines, 0, lines.length);
                        lines = nlines;
                    }

                    lines[linecount++] = layout;
                }
            }

            float basex = insets.left + 10;
            basey += 10;
            g2d.setColor(Color.black);

            for (int i = 0; i < linecount; ++i) {
                TextLayout layout = lines[i];

                basey += layout.getAscent();
                float adv = layout.getAdvance();
                float dx = layout.isLeftToRight() ? 0 : width - adv;

                layout.draw(g2d, basex + dx, basey);

                basey += layout.getDescent() + layout.getLeading();
            }
        }
    }
}