Text blinking cursor hard to see.

Bug 5738416

This problem was introduced in
https://android-git.corp.google.com/g/#/c/152599

The invalidated cursor region is no longer expanded to include the
cursor drawable (different from the handles' drawables).

Added that code back. Added a flag, since invalidateRegion is also
used to invalidate text span regions in spell check (assumes the decorated
span bounds are not bigger that text boundaries), which is fine in case
of underline.

When the cursor is moved on a single line, invalidate the whole line
(same as what was done before). This is sub-optimal, will file a bug
to fix this. The core problem is that we should invalidate the previous
and the new cursor's positions. We only have one of these.

Change-Id: I9ada9340fb52aad3d80c39efd021fd3f9ec0cc4d

Author: Gilles Debunne

core/java/android/widget/SpellChecker.java

@@ -393,7 +393,7 @@ private void createMisspelledSuggestionSpan(Editable editable, SuggestionsInfo s
                 SuggestionSpan.FLAG_EASY_CORRECT | SuggestionSpan.FLAG_MISSPELLED);
         editable.setSpan(suggestionSpan, start, end, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
 
-        mTextView.invalidateRegion(start, end);
+        mTextView.invalidateRegion(start, end, false /* No cursor involved */);
     }
 
     private class SpellParser {

core/java/android/widget/TextView.java

@@ -339,7 +339,7 @@ static class InputMethodState {
 
     private int mCursorDrawableRes;
     private final Drawable[] mCursorDrawable = new Drawable[2];
-    private int mCursorCount; // Actual current number of used mCursorDrawable: 0, 1 or 2
+    private int mCursorCount; // Actual current number of used mCursorDrawable: 0, 1 or 2 (split)
 
     private Drawable mSelectHandleLeft;
     private Drawable mSelectHandleRight;
@@ -4322,7 +4322,7 @@ private void invalidateCursor(int a, int b, int c) {
         if (a >= 0 || b >= 0 || c >= 0) {
             int start = Math.min(Math.min(a, b), c);
             int end = Math.max(Math.max(a, b), c);
-            invalidateRegion(start, end);
+            invalidateRegion(start, end, true /* Also invalidates blinking cursor */);
         }
     }
 
@@ -4331,7 +4331,7 @@ private void invalidateCursor(int a, int b, int c) {
      *
      * @hide
      */
-    void invalidateRegion(int start, int end) {
+    void invalidateRegion(int start, int end, boolean invalidateCursor) {
         if (mLayout == null) {
             invalidate();
         } else {
@@ -4357,11 +4357,19 @@ void invalidateRegion(int start, int end) {
 
                 int bottom = mLayout.getLineBottom(lineEnd);
 
+                if (invalidateCursor) {
+                    for (int i = 0; i < mCursorCount; i++) {
+                        Rect bounds = mCursorDrawable[i].getBounds();
+                        top = Math.min(top, bounds.top);
+                        bottom = Math.max(bottom, bounds.bottom);
+                    }
+                }
+
                 final int compoundPaddingLeft = getCompoundPaddingLeft();
                 final int verticalPadding = getExtendedPaddingTop() + getVerticalOffset(true);
 
                 int left, right;
-                if (lineStart == lineEnd) {
+                if (lineStart == lineEnd && !invalidateCursor) {
                     left = (int) mLayout.getPrimaryHorizontal(start);
                     right = (int) (mLayout.getPrimaryHorizontal(end) + 1.0);
                     left += compoundPaddingLeft;