Merge changes from topics "gesture-preview-highlight", "gesture-preview-impl"

* changes:
  TextView implementation of select and delete gesture previews
  Text highlighting for select and delete gesture previews

3 files changed, 180 insertions, 28 deletions

diff --git a/core/java/android/widget/Editor.java b/core/java/android/widget/Editor.java
index 558d96089bb7..0a3ea8a9f356 100644
--- a/core/java/android/widget/Editor.java
+++ b/core/java/android/widget/Editor.java
@@ -2082,7 +2082,8 @@ public class Editor {
         }
 
         if (selectionHighlight != null && selectionStart == selectionEnd
-                && mDrawableForCursor != null) {
+                && mDrawableForCursor != null
+                && !mTextView.hasGesturePreviewHighlight()) {
             drawCursor(canvas, cursorOffsetVertical);
             // Rely on the drawable entirely, do not draw the cursor line.
             // Has to be done after the IMM related code above which relies on the highlight.
@@ -2714,7 +2715,7 @@ public class Editor {
         unregisterOnBackInvokedCallback();
     }
 
-    private void stopTextActionModeWithPreservingSelection() {
+    void stopTextActionModeWithPreservingSelection() {
         if (mTextActionMode != null) {
             mRestartActionModeOnNextRefresh = true;
         }
diff --git a/core/java/android/widget/TextView.java b/core/java/android/widget/TextView.java
index 475a8491de4d..b9b928e4c2f9 100644
--- a/core/java/android/widget/TextView.java
+++ b/core/java/android/widget/TextView.java
@@ -68,6 +68,7 @@ import android.content.res.XmlResourceParser;
 import android.graphics.BaseCanvas;
 import android.graphics.BlendMode;
 import android.graphics.Canvas;
+import android.graphics.Color;
 import android.graphics.Insets;
 import android.graphics.Matrix;
 import android.graphics.Paint;
@@ -87,6 +88,7 @@ import android.os.AsyncTask;
 import android.os.Build;
 import android.os.Build.VERSION_CODES;
 import android.os.Bundle;
+import android.os.CancellationSignal;
 import android.os.Handler;
 import android.os.LocaleList;
 import android.os.Parcel;
@@ -148,6 +150,7 @@ import android.text.style.SuggestionSpan;
 import android.text.style.URLSpan;
 import android.text.style.UpdateAppearance;
 import android.text.util.Linkify;
+import android.util.ArraySet;
 import android.util.AttributeSet;
 import android.util.DisplayMetrics;
 import android.util.FeatureFlagUtils;
@@ -199,6 +202,7 @@ import android.view.inputmethod.InputConnection;
 import android.view.inputmethod.InputMethodManager;
 import android.view.inputmethod.InsertGesture;
 import android.view.inputmethod.JoinOrSplitGesture;
+import android.view.inputmethod.PreviewableHandwritingGesture;
 import android.view.inputmethod.RemoveSpaceGesture;
 import android.view.inputmethod.SelectGesture;
 import android.view.inputmethod.SelectRangeGesture;
@@ -222,6 +226,7 @@ import android.widget.RemoteViews.RemoteView;
 
 import com.android.internal.accessibility.util.AccessibilityUtils;
 import com.android.internal.annotations.VisibleForTesting;
+import com.android.internal.graphics.ColorUtils;
 import com.android.internal.inputmethod.EditableInputConnection;
 import com.android.internal.logging.MetricsLogger;
 import com.android.internal.logging.nano.MetricsProto.MetricsEvent;
@@ -242,6 +247,7 @@ import java.util.Arrays;
 import java.util.List;
 import java.util.Locale;
 import java.util.Objects;
+import java.util.Set;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.TimeUnit;
 import java.util.function.Consumer;
@@ -931,6 +937,9 @@ public class TextView extends View implements ViewTreeObserver.OnPreDrawListener
     private List<Path> mHighlightPaths;
     private List<Paint> mHighlightPaints;
     private Highlights mHighlights;
+    private int mGesturePreviewHighlightStart = -1;
+    private int mGesturePreviewHighlightEnd = -1;
+    private Paint mGesturePreviewHighlightPaint;
     private final List<Path> mPathRecyclePool = new ArrayList<>();
     private boolean mHighlightPathsBogus = true;
 
@@ -6167,6 +6176,59 @@ public class TextView extends View implements ViewTreeObserver.OnPreDrawListener
     }
 
     /**
+     * Highlights the text range (from inclusive start offset to exclusive end offset) to show what
+     * will be selected by the ongoing select handwriting gesture. While the gesture preview
+     * highlight is shown, the selection or cursor is hidden. If the text or selection is changed,
+     * the gesture preview highlight will be cleared.
+     */
+    private void setSelectGesturePreviewHighlight(int start, int end) {
+        // Selection preview highlight color is the same as selection highlight color.
+        setGesturePreviewHighlight(start, end, mHighlightColor);
+    }
+
+    /**
+     * Highlights the text range (from inclusive start offset to exclusive end offset) to show what
+     * will be deleted by the ongoing delete handwriting gesture. While the gesture preview
+     * highlight is shown, the selection or cursor is hidden. If the text or selection is changed,
+     * the gesture preview highlight will be cleared.
+     */
+    private void setDeleteGesturePreviewHighlight(int start, int end) {
+        // Deletion preview highlight color is 20% opacity of the default text color.
+        int color = mTextColor.getDefaultColor();
+        color = ColorUtils.setAlphaComponent(color, (int) (0.2f * Color.alpha(color)));
+        setGesturePreviewHighlight(start, end, color);
+    }
+
+    private void setGesturePreviewHighlight(int start, int end, int color) {
+        mGesturePreviewHighlightStart = start;
+        mGesturePreviewHighlightEnd = end;
+        if (mGesturePreviewHighlightPaint == null) {
+            mGesturePreviewHighlightPaint = new Paint();
+            mGesturePreviewHighlightPaint.setStyle(Paint.Style.FILL);
+        }
+        mGesturePreviewHighlightPaint.setColor(color);
+
+        if (mEditor != null) {
+            mEditor.hideCursorAndSpanControllers();
+            mEditor.stopTextActionModeWithPreservingSelection();
+        }
+
+        mHighlightPathsBogus = true;
+        invalidate();
+    }
+
+    private void clearGesturePreviewHighlight() {
+        mGesturePreviewHighlightStart = -1;
+        mGesturePreviewHighlightEnd = -1;
+        mHighlightPathsBogus = true;
+        invalidate();
+    }
+
+    boolean hasGesturePreviewHighlight() {
+        return mGesturePreviewHighlightStart > 0;
+    }
+
+    /**
      * Convenience method to append the specified text to the TextView's
      * display buffer, upgrading it to {@link android.widget.TextView.BufferType#EDITABLE}
      * if it was not already editable.
@@ -8300,6 +8362,22 @@ public class TextView extends View implements ViewTreeObserver.OnPreDrawListener
                 }
             }
         }
+
+        if (hasGesturePreviewHighlight()) {
+            final Path path;
+            if (mPathRecyclePool.isEmpty()) {
+                path = new Path();
+            } else {
+                path = mPathRecyclePool.get(mPathRecyclePool.size() - 1);
+                mPathRecyclePool.remove(mPathRecyclePool.size() - 1);
+                path.reset();
+            }
+            mLayout.getSelectionPath(
+                    mGesturePreviewHighlightStart, mGesturePreviewHighlightEnd, path);
+            mHighlightPaths.add(path);
+            mHighlightPaints.add(mGesturePreviewHighlightPaint);
+        }
+
         mHighlightPathsBogus = false;
     }
 
@@ -8503,7 +8581,8 @@ public class TextView extends View implements ViewTreeObserver.OnPreDrawListener
         final int cursorOffsetVertical = voffsetCursor - voffsetText;
 
         maybeUpdateHighlightPaths();
-        Path highlight = getUpdatedHighlightPath();
+        // If there is a gesture preview highlight, then the selection or cursor is not drawn.
+        Path highlight = hasGesturePreviewHighlight() ? null : getUpdatedHighlightPath();
         if (mEditor != null) {
             mEditor.onDraw(canvas, layout, mHighlightPaths, mHighlightPaints, highlight,
                     mHighlightPaint, cursorOffsetVertical);
@@ -9200,6 +9279,14 @@ public class TextView extends View implements ViewTreeObserver.OnPreDrawListener
                 gestures.add(RemoveSpaceGesture.class);
                 gestures.add(JoinOrSplitGesture.class);
                 outAttrs.setSupportedHandwritingGestures(gestures);
+
+                Set<Class<? extends PreviewableHandwritingGesture>> previews = new ArraySet<>();
+                previews.add(SelectGesture.class);
+                previews.add(SelectRangeGesture.class);
+                previews.add(DeleteGesture.class);
+                previews.add(DeleteRangeGesture.class);
+                outAttrs.setSupportedHandwritingGesturePreviews(previews);
+
                 return ic;
             }
         }
@@ -9411,83 +9498,130 @@ public class TextView extends View implements ViewTreeObserver.OnPreDrawListener
     }
 
     /** @hide */
+    public boolean previewHandwritingGesture(
+            @NonNull PreviewableHandwritingGesture gesture,
+            @Nullable CancellationSignal cancellationSignal) {
+        if (gesture instanceof SelectGesture) {
+            performHandwritingSelectGesture((SelectGesture) gesture, /* isPreview= */ true);
+        } else if (gesture instanceof SelectRangeGesture) {
+            performHandwritingSelectRangeGesture(
+                    (SelectRangeGesture) gesture, /* isPreview= */ true);
+        } else if (gesture instanceof DeleteGesture) {
+            performHandwritingDeleteGesture((DeleteGesture) gesture, /* isPreview= */ true);
+        } else if (gesture instanceof DeleteRangeGesture) {
+            performHandwritingDeleteRangeGesture(
+                    (DeleteRangeGesture) gesture, /* isPreview= */ true);
+        } else {
+            return false;
+        }
+        if (cancellationSignal != null) {
+            cancellationSignal.setOnCancelListener(this::clearGesturePreviewHighlight);
+        }
+        return true;
+    }
+
+    /** @hide */
     public int performHandwritingSelectGesture(@NonNull SelectGesture gesture) {
+        return performHandwritingSelectGesture(gesture, /* isPreview= */ false);
+    }
+
+    private int performHandwritingSelectGesture(@NonNull SelectGesture gesture, boolean isPreview) {
         int[] range = getRangeForRect(
                 convertFromScreenToContentCoordinates(gesture.getSelectionArea()),
                 gesture.getGranularity());
         if (range == null) {
-            return handleGestureFailure(gesture);
+            return handleGestureFailure(gesture, isPreview);
+        }
+        return performHandwritingSelectGesture(range, isPreview);
+    }
+
+    private int performHandwritingSelectGesture(int[] range, boolean isPreview) {
+        if (isPreview) {
+            setSelectGesturePreviewHighlight(range[0], range[1]);
+        } else {
+            Selection.setSelection(getEditableText(), range[0], range[1]);
+            mEditor.startSelectionActionModeAsync(/* adjustSelection= */ false);
         }
-        Selection.setSelection(getEditableText(), range[0], range[1]);
-        mEditor.startSelectionActionModeAsync(/* adjustSelection= */ false);
         return InputConnection.HANDWRITING_GESTURE_RESULT_SUCCESS;
     }
 
     /** @hide */
     public int performHandwritingSelectRangeGesture(@NonNull SelectRangeGesture gesture) {
+        return performHandwritingSelectRangeGesture(gesture, /* isPreview= */ false);
+    }
+
+    private int performHandwritingSelectRangeGesture(
+            @NonNull SelectRangeGesture gesture, boolean isPreview) {
         int[] startRange = getRangeForRect(
                 convertFromScreenToContentCoordinates(gesture.getSelectionStartArea()),
                 gesture.getGranularity());
         if (startRange == null) {
-            return handleGestureFailure(gesture);
+            return handleGestureFailure(gesture, isPreview);
         }
         int[] endRange = getRangeForRect(
                 convertFromScreenToContentCoordinates(gesture.getSelectionEndArea()),
                 gesture.getGranularity());
         if (endRange == null) {
-            return handleGestureFailure(gesture);
+            return handleGestureFailure(gesture, isPreview);
         }
         int[] range = new int[] {
                 Math.min(startRange[0], endRange[0]), Math.max(startRange[1], endRange[1])
         };
-        Selection.setSelection(getEditableText(), range[0], range[1]);
-        mEditor.startSelectionActionModeAsync(/* adjustSelection= */ false);
-        return InputConnection.HANDWRITING_GESTURE_RESULT_SUCCESS;
+        return performHandwritingSelectGesture(range, isPreview);
     }
 
     /** @hide */
     public int performHandwritingDeleteGesture(@NonNull DeleteGesture gesture) {
+        return performHandwritingDeleteGesture(gesture, /* isPreview= */ false);
+    }
+
+    private int performHandwritingDeleteGesture(@NonNull DeleteGesture gesture, boolean isPreview) {
         int[] range = getRangeForRect(
                 convertFromScreenToContentCoordinates(gesture.getDeletionArea()),
                 gesture.getGranularity());
         if (range == null) {
-            return handleGestureFailure(gesture);
+            return handleGestureFailure(gesture, isPreview);
         }
+        return performHandwritingDeleteGesture(range, gesture.getGranularity(), isPreview);
+    }
 
-        if (gesture.getGranularity() == HandwritingGesture.GRANULARITY_WORD) {
-            range = adjustHandwritingDeleteGestureRange(range);
-        }
+    private int performHandwritingDeleteGesture(int[] range, int granularity, boolean isPreview) {
+        if (isPreview) {
+            setDeleteGesturePreviewHighlight(range[0], range[1]);
+        } else {
+            if (granularity == HandwritingGesture.GRANULARITY_WORD) {
+                range = adjustHandwritingDeleteGestureRange(range);
+            }
 
-        getEditableText().delete(range[0], range[1]);
-        Selection.setSelection(getEditableText(), range[0]);
+            getEditableText().delete(range[0], range[1]);
+            Selection.setSelection(getEditableText(), range[0]);
+        }
         return InputConnection.HANDWRITING_GESTURE_RESULT_SUCCESS;
     }
 
     /** @hide */
     public int performHandwritingDeleteRangeGesture(@NonNull DeleteRangeGesture gesture) {
+        return performHandwritingDeleteRangeGesture(gesture, /* isPreview= */ false);
+    }
+
+    private int performHandwritingDeleteRangeGesture(
+            @NonNull DeleteRangeGesture gesture, boolean isPreview) {
         int[] startRange = getRangeForRect(
                 convertFromScreenToContentCoordinates(gesture.getDeletionStartArea()),
                 gesture.getGranularity());
         if (startRange == null) {
-            return handleGestureFailure(gesture);
+            return handleGestureFailure(gesture, isPreview);
         }
         int[] endRange = getRangeForRect(
                 convertFromScreenToContentCoordinates(gesture.getDeletionEndArea()),
                 gesture.getGranularity());
         if (endRange == null) {
-            return handleGestureFailure(gesture);
+            return handleGestureFailure(gesture, isPreview);
         }
         int[] range = new int[] {
                 Math.min(startRange[0], endRange[0]), Math.max(startRange[1], endRange[1])
         };
-
-        if (gesture.getGranularity() == HandwritingGesture.GRANULARITY_WORD) {
-            range = adjustHandwritingDeleteGestureRange(range);
-        }
-
-        getEditableText().delete(range[0], range[1]);
-        Selection.setSelection(getEditableText(), range[0]);
-        return InputConnection.HANDWRITING_GESTURE_RESULT_SUCCESS;
+        return performHandwritingDeleteGesture(range, gesture.getGranularity(), isPreview);
     }
 
     private int[] adjustHandwritingDeleteGestureRange(int[] range) {
@@ -9665,7 +9799,12 @@ public class TextView extends View implements ViewTreeObserver.OnPreDrawListener
     }
 
     private int handleGestureFailure(HandwritingGesture gesture) {
-        if (!TextUtils.isEmpty(gesture.getFallbackText())) {
+        return handleGestureFailure(gesture, /* isPreview= */ false);
+    }
+
+    private int handleGestureFailure(HandwritingGesture gesture, boolean isPreview) {
+        clearGesturePreviewHighlight();
+        if (!isPreview && !TextUtils.isEmpty(gesture.getFallbackText())) {
             getEditableText()
                     .replace(getSelectionStart(), getSelectionEnd(), gesture.getFallbackText());
             return InputConnection.HANDWRITING_GESTURE_RESULT_FALLBACK;
@@ -11699,6 +11838,8 @@ public class TextView extends View implements ViewTreeObserver.OnPreDrawListener
         resetErrorChangedFlag();
         sendOnTextChanged(buffer, start, before, after);
         onTextChanged(buffer, start, before, after);
+
+        clearGesturePreviewHighlight();
     }
 
     /**
@@ -11737,6 +11878,7 @@ public class TextView extends View implements ViewTreeObserver.OnPreDrawListener
         }
 
         if (selChanged) {
+            clearGesturePreviewHighlight();
             mHighlightPathBogus = true;
             if (mEditor != null && !isFocused()) mEditor.mSelectionMoved = true;
 
diff --git a/core/java/com/android/internal/inputmethod/EditableInputConnection.java b/core/java/com/android/internal/inputmethod/EditableInputConnection.java
index 330ff8e61609..52e747150789 100644
--- a/core/java/com/android/internal/inputmethod/EditableInputConnection.java
+++ b/core/java/com/android/internal/inputmethod/EditableInputConnection.java
@@ -27,6 +27,7 @@ import android.annotation.NonNull;
 import android.annotation.Nullable;
 import android.graphics.RectF;
 import android.os.Bundle;
+import android.os.CancellationSignal;
 import android.text.Editable;
 import android.text.Selection;
 import android.text.method.KeyListener;
@@ -44,6 +45,7 @@ import android.view.inputmethod.HandwritingGesture;
 import android.view.inputmethod.InputConnection;
 import android.view.inputmethod.InsertGesture;
 import android.view.inputmethod.JoinOrSplitGesture;
+import android.view.inputmethod.PreviewableHandwritingGesture;
 import android.view.inputmethod.RemoveSpaceGesture;
 import android.view.inputmethod.SelectGesture;
 import android.view.inputmethod.SelectRangeGesture;
@@ -321,6 +323,13 @@ public final class EditableInputConnection extends BaseInputConnection
     }
 
     @Override
+    public boolean previewHandwritingGesture(
+            @NonNull PreviewableHandwritingGesture gesture,
+            @Nullable CancellationSignal cancellationSignal) {
+        return mTextView.previewHandwritingGesture(gesture, cancellationSignal);
+    }
+
+    @Override
     public void dumpDebug(ProtoOutputStream proto, long fieldId) {
         final long token = proto.start(fieldId);
         CharSequence editableText = mTextView.getText();