提交: f9c66107fab4e0e4fdebc63924f5fb85c0cd1551 - frameworks-base (git)

frameworks/base

Commit MetaInfo

• 修訂: f9c66107fab4e0e4fdebc63924f5fb85c0cd1551 (tree)
• 時間: 2018-07-20 08:35:40
• 作者: JP Sugarbroad <jpsugar@goog...>
• Commiter: JP Sugarbroad

Log Message

Revert "Optimise the hit test algorithm"

This reverts commit 9dceb027701a1f638484bfeee3749d8399d38918.

Change Summary

• modified: core/java/android/text/Layout.java
• modified: core/java/android/text/TextLine.java

差異

--- a/core/java/android/text/Layout.java
+++ b/core/java/android/text/Layout.java
@@ -824,32 +824,6 @@ public abstract class Layout {
         return TextUtils.packRangeInLong(0, getLineEnd(line));
     }
 
-    /**
-     * Checks if the trailing BiDi level should be used for an offset
-     *
-     * This method is useful when the offset is at the BiDi level transition point and determine
-     * which run need to be used. For example, let's think about following input: (L* denotes
-     * Left-to-Right characters, R* denotes Right-to-Left characters.)
-     * Input (Logical Order): L1 L2 L3 R1 R2 R3 L4 L5 L6
-     * Input (Display Order): L1 L2 L3 R3 R2 R1 L4 L5 L6
-     *
-     * Then, think about selecting the range (3, 6). The offset=3 and offset=6 are ambiguous here
-     * since they are at the BiDi transition point.  In Android, the offset is considered to be
-     * associated with the trailing run if the BiDi level of the trailing run is higher than of the
-     * previous run.  In this case, the BiDi level of the input text is as follows:
-     *
-     * Input (Logical Order): L1 L2 L3 R1 R2 R3 L4 L5 L6
-     *              BiDi Run: [ Run 0 ][ Run 1 ][ Run 2 ]
-     *            BiDi Level:  0  0  0  1  1  1  0  0  0
-     *
-     * Thus, offset = 3 is part of Run 1 and this method returns true for offset = 3, since the BiDi
-     * level of Run 1 is higher than the level of Run 0.  Similarly, the offset = 6 is a part of Run
-     * 1 and this method returns false for the offset = 6 since the BiDi level of Run 1 is higher
-     * than the level of Run 2.
-     *
-     * @returns true if offset is at the BiDi level transition point and trailing BiDi level is
-     *          higher than previous BiDi level. See above for the detail.
-     */
     private boolean primaryIsTrailingPrevious(int offset) {
         int line = getLineForOffset(offset);
         int lineStart = getLineStart(line);
@@ -900,41 +874,6 @@ public abstract class Layout {
     }
 
     /**
-     * Computes in linear time the results of calling
-     * #primaryIsTrailingPrevious for all offsets on a line.
-     * @param line The line giving the offsets we compute the information for
-     * @return The array of results, indexed from 0, where 0 corresponds to the line start offset
-     */
-    private boolean[] primaryIsTrailingPreviousAllLineOffsets(int line) {
-        int lineStart = getLineStart(line);
-        int lineEnd = getLineEnd(line);
-        int[] runs = getLineDirections(line).mDirections;
-
-        boolean[] trailing = new boolean[lineEnd - lineStart + 1];
-
-        byte[] level = new byte[lineEnd - lineStart + 1];
-        for (int i = 0; i < runs.length; i += 2) {
-            int start = lineStart + runs[i];
-            int limit = start + (runs[i + 1] & RUN_LENGTH_MASK);
-            if (limit > lineEnd) {
-                limit = lineEnd;
-            }
-            level[limit - lineStart - 1] =
-                    (byte) ((runs[i + 1] >>> RUN_LEVEL_SHIFT) & RUN_LEVEL_MASK);
-        }
-
-        for (int i = 0; i < runs.length; i += 2) {
-            int start = lineStart + runs[i];
-            byte currentLevel = (byte) ((runs[i + 1] >>> RUN_LEVEL_SHIFT) & RUN_LEVEL_MASK);
-            trailing[start - lineStart] = currentLevel > (start == lineStart
-                    ? (getParagraphDirection(line) == 1 ? 0 : 1)
-                    : level[start - lineStart - 1]);
-        }
-
-        return trailing;
-    }
-
-    /**
      * Get the primary horizontal position for the specified text offset.
      * This is the location where a new character would be inserted in
      * the paragraph's primary direction.
@@ -1014,60 +953,6 @@ public abstract class Layout {
     }
 
     /**
-     * Computes in linear time the results of calling
-     * #getHorizontal for all offsets on a line.
-     * @param line The line giving the offsets we compute information for
-     * @param clamped Whether to clamp the results to the width of the layout
-     * @param primary Whether the results should be the primary or the secondary horizontal
-     * @return The array of results, indexed from 0, where 0 corresponds to the line start offset
-     */
-    private float[] getLineHorizontals(int line, boolean clamped, boolean primary) {
-        int start = getLineStart(line);
-        int end = getLineEnd(line);
-        int dir = getParagraphDirection(line);
-        boolean hasTab = getLineContainsTab(line);
-        Directions directions = getLineDirections(line);
-
-        TabStops tabStops = null;
-        if (hasTab && mText instanceof Spanned) {
-            // Just checking this line should be good enough, tabs should be
-            // consistent across all lines in a paragraph.
-            TabStopSpan[] tabs = getParagraphSpans((Spanned) mText, start, end, TabStopSpan.class);
-            if (tabs.length > 0) {
-                tabStops = new TabStops(TAB_INCREMENT, tabs); // XXX should reuse
-            }
-        }
-
-        TextLine tl = TextLine.obtain();
-        tl.set(mPaint, mText, start, end, dir, directions, hasTab, tabStops);
-        boolean[] trailings = primaryIsTrailingPreviousAllLineOffsets(line);
-        if (!primary) {
-            for (int offset = 0; offset < trailings.length; ++offset) {
-                trailings[offset] = !trailings[offset];
-            }
-        }
-        float[] wid = tl.measureAllOffsets(trailings, null);
-        TextLine.recycle(tl);
-
-        if (clamped) {
-            for (int offset = 0; offset <= wid.length; ++offset) {
-                if (wid[offset] > mWidth) {
-                    wid[offset] = mWidth;
-                }
-            }
-        }
-        int left = getParagraphLeft(line);
-        int right = getParagraphRight(line);
-
-        int lineStartPos = getLineStartPos(line, left, right);
-        float[] horizontal = new float[end - start + 1];
-        for (int offset = 0; offset < horizontal.length; ++offset) {
-            horizontal[offset] = lineStartPos + wid[offset];
-        }
-        return horizontal;
-    }
-
-    /**
      * Get the leftmost position that should be exposed for horizontal
      * scrolling on the specified line.
      */
@@ -1282,8 +1167,6 @@ public abstract class Layout {
         // XXX: we don't care about tabs as we just use TextLine#getOffsetToLeftRightOf here.
         tl.set(mPaint, mText, lineStartOffset, lineEndOffset, getParagraphDirection(line), dirs,
                 false, null);
-        final HorizontalMeasurementProvider horizontal =
-                new HorizontalMeasurementProvider(line, primary);
 
         final int max;
         if (line == getLineCount() - 1) {
@@ -1293,7 +1176,7 @@ public abstract class Layout {
                     !isRtlCharAt(lineEndOffset - 1)) + lineStartOffset;
         }
         int best = lineStartOffset;
-        float bestdist = Math.abs(horizontal.get(lineStartOffset) - horiz);
+        float bestdist = Math.abs(getHorizontal(best, primary) - horiz);
 
         for (int i = 0; i < dirs.mDirections.length; i += 2) {
             int here = lineStartOffset + dirs.mDirections[i];
@@ -1309,7 +1192,7 @@ public abstract class Layout {
                 guess = (high + low) / 2;
                 int adguess = getOffsetAtStartOf(guess);
 
-                if (horizontal.get(adguess) * swap >= horiz * swap)
+                if (getHorizontal(adguess, primary) * swap >= horiz * swap)
                     high = guess;
                 else
                     low = guess;
@@ -1322,9 +1205,9 @@ public abstract class Layout {
                 int aft = tl.getOffsetToLeftRightOf(low - lineStartOffset, isRtl) + lineStartOffset;
                 low = tl.getOffsetToLeftRightOf(aft - lineStartOffset, !isRtl) + lineStartOffset;
                 if (low >= here && low < there) {
-                    float dist = Math.abs(horizontal.get(low) - horiz);
+                    float dist = Math.abs(getHorizontal(low, primary) - horiz);
                     if (aft < there) {
-                        float other = Math.abs(horizontal.get(aft) - horiz);
+                        float other = Math.abs(getHorizontal(aft, primary) - horiz);
 
                         if (other < dist) {
                             dist = other;
@@ -1339,7 +1222,7 @@ public abstract class Layout {
                 }
             }
 
-            float dist = Math.abs(horizontal.get(here) - horiz);
+            float dist = Math.abs(getHorizontal(here, primary) - horiz);
 
             if (dist < bestdist) {
                 bestdist = dist;
@@ -1347,7 +1230,7 @@ public abstract class Layout {
             }
         }
 
-        float dist = Math.abs(horizontal.get(max) - horiz);
+        float dist = Math.abs(getHorizontal(max, primary) - horiz);
 
         if (dist <= bestdist) {
             bestdist = dist;
@@ -1359,46 +1242,6 @@ public abstract class Layout {
     }
 
     /**
-     * Responds to #getHorizontal queries, by selecting the better strategy between:
-     * - calling #getHorizontal explicitly for each query
-     * - precomputing all #getHorizontal measurements, and responding to any query in constant time
-     * The first strategy is used for LTR-only text, while the second is used for all other cases.
-     * The class is currently only used in #getOffsetForHorizontal, so reuse with care in other
-     * contexts.
-     */
-    private class HorizontalMeasurementProvider {
-        private final int mLine;
-        private final boolean mPrimary;
-
-        private float[] mHorizontals;
-        private int mLineStartOffset;
-
-        HorizontalMeasurementProvider(final int line, final boolean primary) {
-            mLine = line;
-            mPrimary = primary;
-            init();
-        }
-
-        private void init() {
-            final Directions dirs = getLineDirections(mLine);
-            if (dirs == DIRS_ALL_LEFT_TO_RIGHT) {
-                return;
-            }
-
-            mHorizontals = getLineHorizontals(mLine, false, mPrimary);
-            mLineStartOffset = getLineStart(mLine);
-        }
-
-        float get(final int offset) {
-            if (mHorizontals == null) {
-                return getHorizontal(offset, mPrimary);
-            } else {
-                return mHorizontals[offset - mLineStartOffset];
-            }
-        }
-    }
-
-    /**
      * Return the text offset after the last character on the specified line.
      */
     public final int getLineEnd(int line) {

--- a/core/java/android/text/TextLine.java
+++ b/core/java/android/text/TextLine.java
@@ -339,98 +339,6 @@ class TextLine {
     }
 
     /**
-     * @see #measure(int, boolean, FontMetricsInt)
-     * @return The measure results for all possible offsets
-     */
-    float[] measureAllOffsets(boolean[] trailing, FontMetricsInt fmi) {
-        float[] measurement = new float[mLen + 1];
-
-        int[] target = new int[mLen + 1];
-        for (int offset = 0; offset < target.length; ++offset) {
-            target[offset] = trailing[offset] ? offset - 1 : offset;
-        }
-        if (target[0] < 0) {
-            measurement[0] = 0;
-        }
-
-        float h = 0;
-
-        if (!mHasTabs) {
-            if (mDirections == Layout.DIRS_ALL_LEFT_TO_RIGHT) {
-                for (int offset = 0; offset <= mLen; ++offset) {
-                    measurement[offset] = measureRun(0, offset, mLen, false, fmi);
-                }
-                return measurement;
-            }
-            if (mDirections == Layout.DIRS_ALL_RIGHT_TO_LEFT) {
-                for (int offset = 0; offset <= mLen; ++offset) {
-                    measurement[offset] = measureRun(0, offset, mLen, true, fmi);
-                }
-                return measurement;
-            }
-        }
-
-        char[] chars = mChars;
-        int[] runs = mDirections.mDirections;
-        for (int i = 0; i < runs.length; i += 2) {
-            int runStart = runs[i];
-            int runLimit = runStart + (runs[i + 1] & Layout.RUN_LENGTH_MASK);
-            if (runLimit > mLen) {
-                runLimit = mLen;
-            }
-            boolean runIsRtl = (runs[i + 1] & Layout.RUN_RTL_FLAG) != 0;
-
-            int segstart = runStart;
-            for (int j = mHasTabs ? runStart : runLimit; j <= runLimit; ++j) {
-                int codept = 0;
-                if (mHasTabs && j < runLimit) {
-                    codept = chars[j];
-                    if (codept >= 0xD800 && codept < 0xDC00 && j + 1 < runLimit) {
-                        codept = Character.codePointAt(chars, j);
-                        if (codept > 0xFFFF) {
-                            ++j;
-                            continue;
-                        }
-                    }
-                }
-
-                if (j == runLimit || codept == '\t') {
-                    float oldh = h;
-                    boolean advance = (mDir == Layout.DIR_RIGHT_TO_LEFT) == runIsRtl;
-                    float w = measureRun(segstart, j, j, runIsRtl, fmi);
-                    h += advance ? w : -w;
-
-                    float baseh = advance ? oldh : h;
-                    FontMetricsInt crtfmi = advance ? fmi : null;
-                    for (int offset = segstart; offset <= j && offset <= mLen; ++offset) {
-                        if (target[offset] >= segstart && target[offset] < j) {
-                            measurement[offset] =
-                                    baseh + measureRun(segstart, offset, j, runIsRtl, crtfmi);
-                        }
-                    }
-
-                    if (codept == '\t') {
-                        if (target[j] == j) {
-                            measurement[j] = h;
-                        }
-                        h = mDir * nextTab(h * mDir);
-                        if (target[j + 1] == j) {
-                            measurement[j + 1] =  h;
-                        }
-                    }
-
-                    segstart = j + 1;
-                }
-            }
-        }
-        if (target[mLen] == mLen) {
-            measurement[mLen] = h;
-        }
-
-        return measurement;
-    }
-
-    /**
      * Draws a unidirectional (but possibly multi-styled) run of text.
      *
      *