core/tests/coretests/src/android/text/LayoutTest.java

/*
 * Copyright (C) 2008 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package android.text;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertNull;
import static org.junit.Assert.assertSame;
import static org.junit.Assert.assertTrue;
import static org.junit.Assert.fail;

import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.Rect;
import android.graphics.RectF;
import android.support.test.filters.SmallTest;
import android.support.test.runner.AndroidJUnit4;
import android.text.Layout.Alignment;
import android.text.style.StrikethroughSpan;

import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;

import java.util.ArrayList;
import java.util.List;

@SmallTest
@RunWith(AndroidJUnit4.class)
public class LayoutTest {
    private static final int LINE_COUNT = 5;
    private static final int LINE_HEIGHT = 12;
    private static final int LINE_DESCENT = 4;
    private static final CharSequence LAYOUT_TEXT = "alwei\t;sdfs\ndf @";

    private SpannableString mSpannedText;

    private int mWidth;
    private Layout.Alignment mAlign;
    private float mSpacingMult;
    private float mSpacingAdd;
    private TextPaint mTextPaint;

    @Before
    public void setup() {
        mTextPaint = new TextPaint();
        mSpannedText = new SpannableString(LAYOUT_TEXT);
        mSpannedText.setSpan(new StrikethroughSpan(), 0, 1, Spannable.SPAN_INCLUSIVE_EXCLUSIVE);
        mWidth = 11;
        mAlign = Alignment.ALIGN_CENTER;
        mSpacingMult = 1;
        mSpacingAdd = 2;
    }

    @Test
    public void testConstructor() {
        new MockLayout(LAYOUT_TEXT, mTextPaint, mWidth, mAlign, mSpacingMult, mSpacingAdd);
    }

    @Test(expected = IllegalArgumentException.class)
    public void testConstructorNull() {
        new MockLayout(null, null, -1, null, 0, 0);
    }

    @Test
    public void testGetText() {
        CharSequence text = "test case 1";
        Layout layout = new MockLayout(text, mTextPaint, mWidth,
                mAlign, mSpacingMult, mSpacingAdd);
        assertEquals(text, layout.getText());

        layout = new MockLayout(null, mTextPaint, mWidth, mAlign, mSpacingMult, mSpacingAdd);
        assertNull(layout.getText());
    }

    @Test
    public void testGetPaint() {
        Layout layout = new MockLayout(LAYOUT_TEXT, mTextPaint, mWidth,
                mAlign, mSpacingMult, mSpacingAdd);

        assertSame(mTextPaint, layout.getPaint());

        layout = new MockLayout(LAYOUT_TEXT, null, mWidth, mAlign, mSpacingMult, mSpacingAdd);
        assertNull(layout.getPaint());
    }

    @Test
    public void testGetWidth() {
        Layout layout = new MockLayout(LAYOUT_TEXT, mTextPaint, 10,
                mAlign, mSpacingMult, mSpacingAdd);
        assertEquals(10,  layout.getWidth());

        layout = new MockLayout(LAYOUT_TEXT, mTextPaint, 0, mAlign, mSpacingMult, mSpacingAdd);
        assertEquals(0,  layout.getWidth());
    }

    @Test
    public void testGetEllipsizedWidth() {
        Layout layout = new MockLayout(LAYOUT_TEXT, mTextPaint, 15,
                mAlign, mSpacingMult, mSpacingAdd);
        assertEquals(15, layout.getEllipsizedWidth());

        layout = new MockLayout(LAYOUT_TEXT, mTextPaint, 0, mAlign, mSpacingMult, mSpacingAdd);
        assertEquals(0,  layout.getEllipsizedWidth());
    }

    @Test
    public void testIncreaseWidthTo() {
        Layout layout = new MockLayout(LAYOUT_TEXT, mTextPaint, mWidth,
                mAlign, mSpacingMult, mSpacingAdd);
        int oldWidth = layout.getWidth();

        layout.increaseWidthTo(oldWidth);
        assertEquals(oldWidth, layout.getWidth());

        try {
            layout.increaseWidthTo(oldWidth - 1);
            fail("should throw runtime exception attempted to reduce Layout width");
        } catch (RuntimeException e) {
        }

        layout.increaseWidthTo(oldWidth + 1);
        assertEquals(oldWidth + 1, layout.getWidth());
    }

    @Test
    public void testGetHeight() {
        Layout layout = new MockLayout(LAYOUT_TEXT, mTextPaint, mWidth,
                mAlign, mSpacingMult, mSpacingAdd);
        assertEquals(60, layout.getHeight());
    }

    @Test
    public void testGetAlignment() {
        Layout layout = new MockLayout(LAYOUT_TEXT, mTextPaint, mWidth,
                mAlign, mSpacingMult, mSpacingAdd);
        assertSame(mAlign, layout.getAlignment());

        layout = new MockLayout(LAYOUT_TEXT, mTextPaint, mWidth, null, mSpacingMult, mSpacingAdd);
        assertNull(layout.getAlignment());
    }

    @Test
    public void testGetSpacingMultiplier() {
        Layout layout = new MockLayout(LAYOUT_TEXT, mTextPaint, mWidth, mAlign, -1, mSpacingAdd);
        assertEquals(-1.0f, layout.getSpacingMultiplier(), 0.0f);

        layout = new MockLayout(LAYOUT_TEXT, mTextPaint, mWidth, mAlign, 5, mSpacingAdd);
        assertEquals(5.0f, layout.getSpacingMultiplier(), 0.0f);
    }

    @Test
    public void testGetSpacingAdd() {
        Layout layout = new MockLayout(LAYOUT_TEXT, mTextPaint, mWidth, mAlign, mSpacingMult, -1);
        assertEquals(-1.0f, layout.getSpacingAdd(), 0.0f);

        layout = new MockLayout(LAYOUT_TEXT, mTextPaint, mWidth, mAlign, mSpacingMult, 20);
        assertEquals(20.0f, layout.getSpacingAdd(), 0.0f);
    }

    @Test
    public void testGetLineBounds() {
        Layout layout = new MockLayout(LAYOUT_TEXT, mTextPaint, mWidth,
                mAlign, mSpacingMult, mSpacingAdd);
        Rect bounds = new Rect();

        assertEquals(32, layout.getLineBounds(2, bounds));
        assertEquals(0, bounds.left);
        assertEquals(mWidth, bounds.right);
        assertEquals(24, bounds.top);
        assertEquals(36, bounds.bottom);
    }

    @Test
    public void testGetLineForVertical() {
        Layout layout = new MockLayout(LAYOUT_TEXT, mTextPaint, mWidth,
                mAlign, mSpacingMult, mSpacingAdd);
        assertEquals(0, layout.getLineForVertical(-1));
        assertEquals(0, layout.getLineForVertical(0));
        assertEquals(0, layout.getLineForVertical(LINE_COUNT));
        assertEquals(LINE_COUNT - 1, layout.getLineForVertical(1000));
    }

    @Test
    public void testGetLineForOffset() {
        Layout layout = new MockLayout(LAYOUT_TEXT, mTextPaint, mWidth,
                mAlign, mSpacingMult, mSpacingAdd);
        assertEquals(0, layout.getLineForOffset(-1));
        assertEquals(1, layout.getLineForOffset(1));
        assertEquals(LINE_COUNT - 1, layout.getLineForOffset(LINE_COUNT - 1));
        assertEquals(LINE_COUNT - 1, layout.getLineForOffset(1000));
    }

    @Test
    public void testGetLineEnd() {
        Layout layout = new MockLayout(LAYOUT_TEXT, mTextPaint, mWidth,
                mAlign, mSpacingMult, mSpacingAdd);
        assertEquals(2, layout.getLineEnd(1));
    }

    @Test
    public void testGetLineVisibleEnd() {
        Layout layout = new MockLayout(LAYOUT_TEXT, mTextPaint, mWidth,
                mAlign, mSpacingMult, mSpacingAdd);

        assertEquals(2, layout.getLineVisibleEnd(1));
        assertEquals(LINE_COUNT, layout.getLineVisibleEnd(LINE_COUNT - 1));
        assertEquals(LAYOUT_TEXT.length(), layout.getLineVisibleEnd(LAYOUT_TEXT.length() - 1));
        try {
            layout.getLineVisibleEnd(LAYOUT_TEXT.length());
            fail("should throw .StringIndexOutOfBoundsException here");
        } catch (StringIndexOutOfBoundsException e) {
        }
    }

    @Test
    public void testGetLineBottom() {
        Layout layout = new MockLayout(LAYOUT_TEXT, mTextPaint, mWidth,
                mAlign, mSpacingMult, mSpacingAdd);
        assertEquals(LINE_HEIGHT, layout.getLineBottom(0));
    }

    @Test
    public void testGetLineBaseline() {
        Layout layout = new MockLayout(LAYOUT_TEXT, mTextPaint, mWidth,
                mAlign, mSpacingMult, mSpacingAdd);
        assertEquals(8, layout.getLineBaseline(0));
    }

    @Test
    public void testGetLineAscent() {
        Layout layout = new MockLayout(LAYOUT_TEXT, mTextPaint, mWidth,
                mAlign, mSpacingMult, mSpacingAdd);
        assertEquals(-8, layout.getLineAscent(0));
    }

    @Test
    public void testGetParagraphAlignment() {
        Layout layout = new MockLayout(LAYOUT_TEXT, mTextPaint, mWidth,
                mAlign, mSpacingMult, mSpacingAdd);
        assertSame(mAlign, layout.getParagraphAlignment(0));

        layout = new MockLayout(mSpannedText, mTextPaint, mWidth,
                mAlign, mSpacingMult, mSpacingAdd);
        assertSame(mAlign, layout.getParagraphAlignment(0));
        assertSame(mAlign, layout.getParagraphAlignment(1));
    }

    @Test
    public void testGetParagraphLeft() {
        Layout layout = new MockLayout(LAYOUT_TEXT, mTextPaint, mWidth,
                mAlign, mSpacingMult, mSpacingAdd);
        assertEquals(0, layout.getParagraphLeft(0));
    }

    @Test
    public void testGetParagraphRight() {
        Layout layout = new MockLayout(LAYOUT_TEXT, mTextPaint, mWidth,
                mAlign, mSpacingMult, mSpacingAdd);
        assertEquals(mWidth, layout.getParagraphRight(0));
    }

    @Test
    public void testIsSpanned() {
        MockLayout layout = new MockLayout(LAYOUT_TEXT, mTextPaint, mWidth,
                mAlign, mSpacingMult, mSpacingAdd);
        // default is not spanned text
        assertFalse(layout.mockIsSpanned());

        // try to create a spanned text
        layout = new MockLayout(mSpannedText, mTextPaint, mWidth,
                mAlign, mSpacingMult, mSpacingAdd);
        assertTrue(layout.mockIsSpanned());
    }

    private static final class MockLayout extends Layout {
        MockLayout(CharSequence text, TextPaint paint, int width,
                Alignment align, float spacingmult, float spacingadd) {
            super(text, paint, width, align, spacingmult, spacingadd);
        }

        protected boolean mockIsSpanned() {
            return super.isSpanned();
        }

        @Override
        public int getBottomPadding() {
            return 0;
        }

        @Override
        public int getEllipsisCount(int line) {
            return 0;
        }

        @Override
        public int getEllipsisStart(int line) {
            return 0;
        }

        @Override
        public boolean getLineContainsTab(int line) {
            return false;
        }

        @Override
        public int getLineCount() {
            return LINE_COUNT;
        }

        @Override
        public int getLineDescent(int line) {
            return LINE_DESCENT;
        }

        @Override
        public Directions getLineDirections(int line) {
            return Layout.DIRS_ALL_LEFT_TO_RIGHT;
        }

        @Override
        public int getLineStart(int line) {
            if (line < 0) {
                return 0;
            }
            return line;
        }

        @Override
        public int getLineTop(int line) {
            if (line < 0) {
                return 0;
            }
            return LINE_HEIGHT * (line);
        }

        @Override
        public int getParagraphDirection(int line) {
            return 0;
        }

        @Override
        public int getTopPadding() {
            return 0;
        }
    }

    @Test
    public void testGetLineWidth() {
        Layout layout = new MockLayout(LAYOUT_TEXT, mTextPaint, mWidth,
                mAlign, mSpacingMult, mSpacingAdd);
        for (int i = 0; i < LINE_COUNT; i++) {
            int start = layout.getLineStart(i);
            int end = layout.getLineEnd(i);
            String text = LAYOUT_TEXT.toString().substring(start, end);
            assertEquals(mTextPaint.measureText(text), layout.getLineWidth(i), 1.0f);
        }
    }

    @Test
    public void testGetCursorPath() {
        Layout layout = new MockLayout(LAYOUT_TEXT, mTextPaint, mWidth,
                mAlign, mSpacingMult, mSpacingAdd);
        Path path = new Path();
        final float epsilon = 1.0f;
        for (int i = 0; i < LINE_COUNT; i++) {
            layout.getCursorPath(i, path, LAYOUT_TEXT);
            RectF bounds = new RectF();
            path.computeBounds(bounds, false);
            assertTrue(bounds.top >= layout.getLineTop(i) - epsilon);
            assertTrue(bounds.bottom <= layout.getLineBottom(i) + epsilon);
        }
    }

    @Test
    public void testDraw() {
        Layout layout = new MockLayout(LAYOUT_TEXT, mTextPaint, mWidth,
                mAlign, mSpacingMult, mSpacingAdd);
        final int width = 256;
        final int height = 256;
        MockCanvas c = new MockCanvas(width, height);
        layout.draw(c);
        List<MockCanvas.DrawCommand> drawCommands = c.getDrawCommands();
        assertEquals(LINE_COUNT, drawCommands.size());
        for (int i = 0; i < LINE_COUNT; i++) {
            MockCanvas.DrawCommand drawCommand = drawCommands.get(i);
            int start = layout.getLineStart(i);
            int end = layout.getLineEnd(i);
            assertEquals(LAYOUT_TEXT.toString().substring(start, end), drawCommand.text);
            float expected_y = (i + 1) * LINE_HEIGHT - LINE_DESCENT;
            assertEquals(expected_y, drawCommand.y, 0.0f);
        }
    }

    private final class MockCanvas extends Canvas {

        class DrawCommand {
            public final String text;
            public final float x;
            public final float y;

            DrawCommand(String text, float x, float y) {
                this.text = text;
                this.x = x;
                this.y = y;
            }
        }

        List<DrawCommand> mDrawCommands;

        MockCanvas(int width, int height) {
            super();
            mDrawCommands = new ArrayList<>();
            Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
            setBitmap(bitmap);
        }

        // Drawing text with either drawText or drawTextRun is valid; we don't care which.
        // We also don't care which of the string representations is used.

        @Override
        public void drawText(String text, int start, int end, float x, float y, Paint p) {
            mDrawCommands.add(new DrawCommand(text.substring(start, end), x, y));
        }

        @Override
        public void drawText(CharSequence text, int start, int end, float x, float y, Paint p) {
            drawText(text.toString(), start, end, x, y, p);
        }

        @Override
        public void drawText(char[] text, int index, int count, float x, float y, Paint p) {
            mDrawCommands.add(new DrawCommand(new String(text, index, count), x, y));
        }

        @Override
        public void drawTextRun(CharSequence text, int start, int end, int contextStart,
                int contextEnd, float x, float y, boolean isRtl, Paint paint) {
            drawText(text, start, end, x, y, paint);
        }

        @Override
        public void drawTextRun(char[] text, int index, int count, int contextIndex,
                int contextCount, float x, float y, boolean isRtl, Paint paint) {
            drawText(text, index, count, x, y, paint);
        }

        List<DrawCommand> getDrawCommands() {
            return mDrawCommands;
        }
    }
}