Merge "Use bidi heuristics correctly in BoringLayout#isBoring()" (61b54967) · Commits · e / os / android_frameworks_base

core/java/android/text/BoringLayout.java

+58 −67

Original line number	Diff line number	Diff line
		@@ -220,16 +220,6 @@ public class BoringLayout extends Layout implements TextUtils.EllipsizeCallback
		return isBoring(text, paint, TextDirectionHeuristics.FIRSTSTRONG_LTR, null);
		}

		/**
		* Returns null if not boring; the width, ascent, and descent if boring.
		* @hide
		*/
		public static Metrics isBoring(CharSequence text,
		TextPaint paint,
		TextDirectionHeuristic textDir) {
		return isBoring(text, paint, textDir, null);
		}

		/**
		* Returns null if not boring; the width, ascent, and descent in the
		* provided Metrics object (or a new one if the provided one was null)
		@@ -240,24 +230,18 @@ public class BoringLayout extends Layout implements TextUtils.EllipsizeCallback
		}

		/**
		* Returns null if not boring; the width, ascent, and descent in the
		* provided Metrics object (or a new one if the provided one was null)
		* if boring.
		* @hide
		* Returns true if the text contains any RTL characters, bidi format characters, or surrogate
		* code units.
		*/
		public static Metrics isBoring(CharSequence text, TextPaint paint,
		TextDirectionHeuristic textDir, Metrics metrics) {
		private static boolean hasAnyInterestingChars(CharSequence text, int textLength) {
		final int MAX_BUF_LEN = 500;
		final char[] buffer = TextUtils.obtain(MAX_BUF_LEN);
		final int textLength = text.length();
		boolean boring = true;

		outer:
		try {
		for (int start = 0; start < textLength; start += MAX_BUF_LEN) {
		final int end = Math.min(start + MAX_BUF_LEN, textLength);

		// No need to worry about getting half codepoints, since we reject surrogate code units
		// as non-boring as soon we see one.
		// No need to worry about getting half codepoints, since we consider surrogate code
		// units "interesting" as soon we see one.
		TextUtils.getChars(text, start, end, buffer, 0);

		final int len = end - start;
		@@ -266,6 +250,7 @@ public class BoringLayout extends Layout implements TextUtils.EllipsizeCallback

		if (c == '\n' \|\| c == '\t' \|\|
		(c >= 0x0590 && c <= 0x08FF) \|\| // RTL scripts
		c == 0x200E \|\| // Bidi format character
		c == 0x200F \|\| // Bidi format character
		(c >= 0x202A && c <= 0x202E) \|\| // Bidi format characters
		(c >= 0x2066 && c <= 0x2069) \|\| // Bidi format characters
		@@ -273,30 +258,39 @@ public class BoringLayout extends Layout implements TextUtils.EllipsizeCallback
		(c >= 0xFB1D && c <= 0xFDFF) \|\| // Hebrew and Arabic presentation forms
		(c >= 0xFE70 && c <= 0xFEFE) // Arabic presentation forms
		) {
		boring = false;
		break outer;
		return true;
		}
		}

		// TODO: This looks a little suspicious, and in some cases can result in O(n^2)
		// run time. Consider moving outside the loop.
		if (textDir != null && textDir.isRtl(buffer, 0, len)) {
		boring = false;
		break outer;
		}
		}

		return false;
		} finally {
		TextUtils.recycle(buffer);
		}
		}

		if (boring && text instanceof Spanned) {
		/**
		* Returns null if not boring; the width, ascent, and descent in the
		* provided Metrics object (or a new one if the provided one was null)
		* if boring.
		* @hide
		*/
		public static Metrics isBoring(CharSequence text, TextPaint paint,
		TextDirectionHeuristic textDir, Metrics metrics) {
		final int textLength = text.length();
		if (hasAnyInterestingChars(text, textLength)) {
		return null; // There are some interesting characters. Not boring.
		}
		if (textDir != null && textDir.isRtl(text, 0, textLength)) {
		return null; // The heuristic considers the whole text RTL. Not boring.
		}
		if (text instanceof Spanned) {
		Spanned sp = (Spanned) text;
		Object[] styles = sp.getSpans(0, textLength, ParagraphStyle.class);
		if (styles.length > 0) {
		boring = false;
		return null; // There are some PargraphStyle spans. Not boring.
		}
		}

		if (boring) {
		Metrics fm = metrics;
		if (fm == null) {
		fm = new Metrics();
		@@ -311,9 +305,6 @@ public class BoringLayout extends Layout implements TextUtils.EllipsizeCallback
		TextLine.recycle(line);

		return fm;
		} else {
		return null;
		}
		}

		@Override