Reorganize MeasuredText API

This CL changes the MeasuredText API:
- Rename MeasuredText to PrecomputedText.
- PrecomputedText is no longer a Spanned.
- Introduce PrecomputedText.Param which holds all text layout parameters.
- Add API to get PrecomputedText.Param from TextView.
- Remove MeasuredText.Builder and add PrecomputedText.create method instead.
- Remove setRange from MeasuredText since it is not for normal use case.
  (It can not be used for TextView)

Here is a performance scores: (median, walleye-userdebug, N=20)

StaticLayout creation time (w/o patch -> w/ patch)
 PrecomputedText Balanced Hyphenation  :    743,615 ->    737,145: (-0.9%)
 PrecomputedText Balanced NoHyphenation:    551,544 ->    542,715: (-1.6%)
 PrecomputedText Greedy Hyphenation    :    500,343 ->    499,601: (-0.1%)
 PrecomputedText Greedy NoHyphenation  :    497,987 ->    492,587: (-1.1%)
 RandomText Balanced Hyphenation       : 19,100,592 -> 19,135,289: (+0.2%)
 RandomText Balanced NoHyphenation     :  8,015,088 ->  7,954,260: (-0.8%)
 RandomText Greedy Hyphenation         :  7,950,915 ->  7,877,424: (-0.9%)
 RandomText Greedy NoHyphenation       :  7,939,337 ->  7,863,471: (-1.0%)

PrecomputedText creation time (w/o patch -> w/ patch)
 NoStyled Hyphenation                  : 18,935,638 -> 18,925,422: (-0.1%)
 NoStyled Hyphenation WidthOnly        : 18,469,726 -> 18,978,413: (+2.8%)
 NoStyled NoHyphenation                :  7,940,792 ->  7,919,127: (-0.3%)
 NoStyled NoHyphenation WidthOnly      :  7,463,230 ->  7,922,643: (+6.2%)
 Styled Hyphenation                    : 14,822,501 -> 14,809,017: (-0.1%)
 Styled Hyphenation WidthOnly          : 13,891,770 -> 14,656,617: (+5.5%)
 Styled NoHyphenation                  : 14,511,134 -> 14,301,503: (-1.4%)
 Styled NoHyphenation WidthOnly        : 13,495,345 -> 14,264,314: (+5.7%)

StaticLayout draw time (w/o patch -> w/ patch)
 PrecomputedText NoStyled              :    663,974 ->    661,610: (-0.4%)
 PrecomputedText NoStyled WithoutCache :    648,294 ->    648,766: (+0.1%)
 PrecomputedText Styled                :    879,322 ->    852,770: (-3.0%)
 PrecomputedText Styled WithoutCache   :  1,084,570 ->  1,110,147: (+2.4%)
 RandomText NoStyled                   :    565,682 ->    555,435: (-1.8%)
 RandomText NoStyled WithoutCache      :  9,070,533 ->  9,064,825: (-0.1%)
 RandomText Styled                     :  2,955,202 ->  2,962,008: (+0.2%)
 RandomText Styled WithoutCache        : 12,242,325 -> 12,228,573: (-0.1%)

Bug: 67504091
Bug: 73091756
Test: bit FrameworksCoreTests:android.text.
Test: atest CtsWidgetTestCases:EditTextTest \
    CtsWidgetTestCases:TextViewFadingEdgeTest \
    FrameworksCoreTests:TextViewFallbackLineSpacingTest \
    FrameworksCoreTests:TextViewTest FrameworksCoreTests:TypefaceTest \
    CtsGraphicsTestCases:TypefaceTest CtsWidgetTestCases:TextViewTest \
    CtsTextTestCases
Change-Id: I7db9e2ca4db68a16648cfb8fcf63555f501304c2

1 files changed, 94 insertions, 7 deletions

diff --git a/core/java/android/widget/TextView.java b/core/java/android/widget/TextView.java
index 5710db3ce8e0..f6e771a9605e 100644
--- a/core/java/android/widget/TextView.java
+++ b/core/java/android/widget/TextView.java
@@ -80,8 +80,8 @@ import android.text.GraphicsOperations;
 import android.text.InputFilter;
 import android.text.InputType;
 import android.text.Layout;
-import android.text.MeasuredText;
 import android.text.ParcelableSpan;
+import android.text.PrecomputedText;
 import android.text.Selection;
 import android.text.SpanWatcher;
 import android.text.Spannable;
@@ -637,6 +637,7 @@ public class TextView extends View implements ViewTreeObserver.OnPreDrawListener
     private CharSequence mText;
     private CharSequence mTransformed;
     private BufferType mBufferType = BufferType.NORMAL;
+    private PrecomputedText mPrecomputed;
 
     private CharSequence mHint;
     private Layout mHintLayout;
@@ -4085,6 +4086,80 @@ public class TextView extends View implements ViewTreeObserver.OnPreDrawListener
     }
 
     /**
+     * Gets the parameters for text layout precomputation, for use with {@link PrecomputedText}
+     *
+     * @return A current {@link PrecomputedText.Params}
+     */
+    public @NonNull PrecomputedText.Params getTextMetricsParams() {
+        return new PrecomputedText.Params(new TextPaint(mTextPaint), getTextDirectionHeuristic(),
+                mBreakStrategy, mHyphenationFrequency);
+    }
+
+    /**
+     * Apply the text layout parameter.
+     */
+    public void setTextMetricsParams(@NonNull PrecomputedText.Params params) {
+        mTextPaint.set(params.getTextPaint());
+        mTextDir = params.getTextDirection();
+        mBreakStrategy = params.getBreakStrategy();
+        mHyphenationFrequency = params.getHyphenationFrequency();
+        if (mLayout != null) {
+            nullLayouts();
+            requestLayout();
+            invalidate();
+        }
+    }
+
+    /**
+     * Sets the precomputed text.
+     *
+     * If the parameters for the precomputed text is different from current text view parameters,
+     * apply the parameteres to the text view too.
+     *
+     * @param text A precomputed text.
+     */
+    public void setPrecomputedTextAndParams(@NonNull PrecomputedText text) {
+        Preconditions.checkNotNull(text);
+        final PrecomputedText.Params params = text.getParams();
+        if (!params.sameTextMetrics(getTextMetricsParams())) {
+            setTextMetricsParams(params);
+        }
+        setText(text.getText());
+        if (mTransformed != text.getText()) {
+            // setText modified given text for some reasons, selection, transformation, etc.
+            // Can't use computed result.
+            return;
+        } else {
+            mPrecomputed = text;
+        }
+    }
+
+    /**
+     * Sets the precomputed text.
+     *
+     * If the parameters for the precomputed text is different from current text view parameters,
+     * throws {@link IllegalArgumentException}.
+     *
+     * @param text A precomputed text.
+     */
+    public void setPrecomputedTextOrThrow(@NonNull PrecomputedText text) {
+        Preconditions.checkNotNull(text);
+        final PrecomputedText.Params params = text.getParams();
+        if (!params.sameTextMetrics(getTextMetricsParams())) {
+            throw new IllegalArgumentException(
+                "The precomputed configuration is different from this TextView.");
+        }
+        setText(text.getText());
+        if (mTransformed != text.getText()) {
+            // setText modified given text for some reasons, selection, transformation, etc.
+            // Can't use computed result.
+            // TODO: Do we throw an exception here too?
+        } else {
+            mPrecomputed = text;
+        }
+    }
+
+    /**
      * Set justification mode. The default value is {@link Layout#JUSTIFICATION_MODE_NONE}. If the
      * last line is too short for justification, the last line will be displayed with the
      * alignment set by {@link android.view.View#setTextAlignment}.
@@ -5519,6 +5594,7 @@ public class TextView extends View implements ViewTreeObserver.OnPreDrawListener
 
     private void setText(CharSequence text, BufferType type,
                          boolean notifyBefore, int oldlen) {
+        mPrecomputed = null;
         mTextSetFromXmlOrResourceId = false;
         if (text == null) {
             text = "";
@@ -5577,7 +5653,7 @@ public class TextView extends View implements ViewTreeObserver.OnPreDrawListener
             if (imm != null) imm.restartInput(this);
         } else if (type == BufferType.SPANNABLE || mMovement != null) {
             text = mSpannableFactory.newSpannable(text);
-        } else if (!(text instanceof MeasuredText || text instanceof CharWrapper)) {
+        } else if (!(text instanceof CharWrapper)) {
             text = TextUtils.stringOrSpannedString(text);
         }
 
@@ -8244,7 +8320,8 @@ public class TextView extends View implements ViewTreeObserver.OnPreDrawListener
             result = builder.build();
         } else {
             if (boring == UNKNOWN_BORING) {
-                boring = BoringLayout.isBoring(mTransformed, mTextPaint, mTextDir, mBoring);
+                boring = BoringLayout.isBoring(mTransformed, mPrecomputed, mTextPaint, mTextDir,
+                        mBoring);
                 if (boring != null) {
                     mBoring = boring;
                 }
@@ -8282,9 +8359,15 @@ public class TextView extends View implements ViewTreeObserver.OnPreDrawListener
             }
         }
         if (result == null) {
-            StaticLayout.Builder builder = StaticLayout.Builder.obtain(mTransformed,
-                    0, mTransformed.length(), mTextPaint, wantWidth)
-                    .setAlignment(alignment)
+            StaticLayout.Builder builder;
+            if (mPrecomputed != null) {
+                builder = StaticLayout.Builder.obtain(mPrecomputed, 0,
+                        mPrecomputed.getText().length(), mTextPaint, wantWidth);
+            } else {
+                builder = StaticLayout.Builder.obtain(mTransformed, 0, mTransformed.length(),
+                        mTextPaint, wantWidth);
+            }
+            builder.setAlignment(alignment)
                     .setTextDirection(mTextDir)
                     .setLineSpacing(mSpacingAdd, mSpacingMult)
                     .setIncludePad(mIncludePad)
@@ -8411,7 +8494,8 @@ public class TextView extends View implements ViewTreeObserver.OnPreDrawListener
             }
 
             if (des < 0) {
-                boring = BoringLayout.isBoring(mTransformed, mTextPaint, mTextDir, mBoring);
+                boring = BoringLayout.isBoring(mTransformed, mPrecomputed, mTextPaint, mTextDir,
+                        mBoring);
                 if (boring != null) {
                     mBoring = boring;
                 }
@@ -11696,6 +11780,9 @@ public class TextView extends View implements ViewTreeObserver.OnPreDrawListener
     }
 
     /**
+     * Returns the current {@link TextDirectionHeuristic}
+     *
+     * @return A {@link TextDirectionHeuristic}.
      * @hide
      */
     protected TextDirectionHeuristic getTextDirectionHeuristic() {