am d642de58: am ec4623d0: Improve text rendering and measurement. [DO NOT MERGE]

import com.ibm.icu.lang.UScriptRun;

import android.graphics.Paint_Delegate.FontInfo;

import android.graphics.RectF;;

/**

 * Render the text by breaking it into various scripts and using the right font for each script.

        }

    }

    private Graphics2D graphics;

    private Paint_Delegate paint;

    private char[] text;

    private Graphics2D mGraphics;

    private Paint_Delegate mPaint;

    private char[] mText;

    // Bounds of the text drawn so far.

    private RectF bounds;

    private RectF mBounds;

    private float mBaseline;

    /**

     * @param graphics May be null.

     */

    /* package */ BidiRenderer(Graphics2D graphics, Paint_Delegate paint, char[] text) {

        assert (paint != null);

        this.graphics = graphics;

        this.paint = paint;

        this.text = text;

        mGraphics = graphics;

        mPaint = paint;

        mText = text;

    }

    /**

     * @param advances If not null, then advances for each character to be rendered are returned

     *            here.

     * @param advancesIndex index into advances from where the advances need to be filled.

     * @param draw If true and {@link graphics} is not null, draw the rendered text on the graphics

     * @param draw If true and {@code graphics} is not null, draw the rendered text on the graphics

     *            at the given co-ordinates

     * @param x The x-coordinate of the left edge of where the text should be drawn on the given

     *            graphics.

     * @param y The y-coordinate at which to draw the text on the given graphics.

     * @param y The y-coordinate at which to draw the text on the given mGraphics.

     * @return A rectangle specifying the bounds of the text drawn.

     */

    /* package */ RectF renderText(int start, int limit, boolean isRtl, float advances[],

    /* package */ RectF renderText(int start, int limit, boolean isRtl, float[] advances,

            int advancesIndex, boolean draw, float x, float y) {

        // We break the text into scripts and then select font based on it and then render each of

        // the script runs.

        bounds = new RectF(x, y, x, y);

        for (ScriptRun run : getScriptRuns(text, start, limit, isRtl, paint.getFonts())) {

        mBounds = new RectF(x, y, x, y);

        mBaseline = y;

        for (ScriptRun run : getScriptRuns(mText, start, limit, isRtl, mPaint.getFonts())) {

            int flag = Font.LAYOUT_NO_LIMIT_CONTEXT | Font.LAYOUT_NO_START_CONTEXT;

            flag |= isRtl ? Font.LAYOUT_RIGHT_TO_LEFT : Font.LAYOUT_LEFT_TO_RIGHT;

            renderScript(run.start, run.limit, run.font, flag, advances, advancesIndex, draw);

            advancesIndex += run.limit - run.start;

        }

        return bounds;

        return mBounds;

    }

    /**

     * be drawn using the preferred font.

     */

    private void renderScript(int start, int limit, FontInfo preferredFont, int flag,

            float advances[], int advancesIndex, boolean draw) {

        List<FontInfo> fonts = paint.getFonts();

            float[] advances, int advancesIndex, boolean draw) {

        List<FontInfo> fonts = mPaint.getFonts();

        if (fonts == null || preferredFont == null) {

            return;

        }

        while (start < limit) {

            boolean foundFont = false;

            int canDisplayUpTo = preferredFont.mFont.canDisplayUpTo(text, start, limit);

            int canDisplayUpTo = preferredFont.mFont.canDisplayUpTo(mText, start, limit);

            if (canDisplayUpTo == -1) {

                // We can draw all characters in the text.

                render(start, limit, preferredFont, flag, advances, advancesIndex, draw);

                return;

            } else if (canDisplayUpTo > start) { // can draw something

            }

            if (canDisplayUpTo > start) {

                // We can draw something.

                render(start, canDisplayUpTo, preferredFont, flag, advances, advancesIndex, draw);

                advancesIndex += canDisplayUpTo - start;

                start = canDisplayUpTo;

            // The current character cannot be drawn with the preferred font. Cycle through all the

            // fonts to check which one can draw it.

            int charCount = Character.isHighSurrogate(text[start]) ? 2 : 1;

            int charCount = Character.isHighSurrogate(mText[start]) ? 2 : 1;

            for (FontInfo font : fonts) {

                canDisplayUpTo = font.mFont.canDisplayUpTo(text, start, start + charCount);

                canDisplayUpTo = font.mFont.canDisplayUpTo(mText, start, start + charCount);

                if (canDisplayUpTo == -1) {

                    render(start, start+charCount, font, flag, advances, advancesIndex, draw);

                    start += charCount;

    }

    /**

     * Render the text with the given font to the right of the bounds passed.

     * Renders the text to the right of the bounds with the given font.

     * @param font The font to render the text with.

     */

    private void render(int start, int limit, FontInfo font, int flag, float advances[],

    private void render(int start, int limit, FontInfo font, int flag, float[] advances,

            int advancesIndex, boolean draw) {

        // Since the metrics don't have anti-aliasing set, we create a new FontRenderContext with

        // the anti-aliasing set.

        FontRenderContext f = font.mMetrics.getFontRenderContext();

        FontRenderContext frc = new FontRenderContext(f.getTransform(), paint.isAntiAliased(),

        FontRenderContext frc = new FontRenderContext(f.getTransform(), mPaint.isAntiAliased(),

                f.usesFractionalMetrics());

        GlyphVector gv = font.mFont.layoutGlyphVector(frc, text, start, limit, flag);

        GlyphVector gv = font.mFont.layoutGlyphVector(frc, mText, start, limit, flag);

        int ng = gv.getNumGlyphs();

        int[] ci = gv.getGlyphCharIndices(0, ng, null);

        for (int i = 0; i < ng; i++) {

            float adv = gv.getGlyphMetrics(i).getAdvanceX();

        if (advances != null) {

            for (int i = 0; i < ng; i++) {

                int adv_idx = advancesIndex + ci[i];

                advances[adv_idx] += adv;

                advances[adv_idx] += gv.getGlyphMetrics(i).getAdvanceX();

            }

        }

        if (draw && graphics != null) {

            graphics.drawGlyphVector(gv, bounds.right, bounds.bottom);

        if (draw && mGraphics != null) {

            mGraphics.drawGlyphVector(gv, mBounds.right, mBaseline);

        }

        Rectangle2D awtBounds = gv.getVisualBounds();

        RectF visualBounds = awtRectToAndroidRect(awtBounds, bounds.right, bounds.bottom);

        // If the width of the bounds is zero, no text has been drawn yet. Hence, use the

        // coordinates from the bounds as an offset only.

        if (Math.abs(bounds.right - bounds.left) == 0) {

            bounds = visualBounds;

        // Update the bounds.

        Rectangle2D awtBounds = gv.getLogicalBounds();

        RectF bounds = awtRectToAndroidRect(awtBounds, mBounds.right, mBaseline);

        // If the width of the bounds is zero, no text had been drawn earlier. Hence, use the

        // coordinates from the bounds as an offset.

        if (Math.abs(mBounds.right - mBounds.left) == 0) {

            mBounds = bounds;

        } else {

            bounds.union(visualBounds);

            mBounds.union(bounds);

        }

    }

    private RectF awtRectToAndroidRect(Rectangle2D awtRec, float offsetX, float offsetY) {

    // --- Static helper methods ---

    private static RectF awtRectToAndroidRect(Rectangle2D awtRec, float offsetX, float offsetY) {

        float left = (float) awtRec.getX();

        float top = (float) awtRec.getY();

        float right = (float) (left + awtRec.getWidth());

        return androidRect;

    }

    // --- Static helper methods ---

    /* package */  static List<ScriptRun> getScriptRuns(char[] text, int start, int limit,

            boolean isRtl, List<FontInfo> fonts) {

        LinkedList<ScriptRun> scriptRuns = new LinkedList<ScriptRun>();