refine text selection

Change 'select all' to begin with the first character and end
with the last rather than relying on the top left and bottom
right. The old algorithm failed for pages broken into multiple
columns.

Similarly, capture the text from the beginning selection to the
ending selection, rather than relying on the characters contained
by the selection region.

Reduce the gap required to add a linebreak from twice the
lineheight to 1.5x the lineheight.

Change-Id: Ib90a719ea3353feeaa3a6cc692d0dd9cff498cb5
http://b/262451

1 files changed, 26 insertions, 24 deletions

diff --git a/WebKit/android/nav/SelectText.cpp b/WebKit/android/nav/SelectText.cpp
index 011349e..7d2aaa7 100644
--- a/WebKit/android/nav/SelectText.cpp
+++ b/WebKit/android/nav/SelectText.cpp
@@ -221,7 +221,8 @@ public:
     bool addNewLine(const SkBounder::GlyphRec& rec)
     {
         SkFixed lineSpacing = SkFixedAbs(mLastGlyph.fLSB.fY - rec.fLSB.fY);
-        return lineSpacing >= SkIntToFixed((bottom() - top()) * 2);
+        SkFixed lineHeight = SkIntToFixed(bottom() - top());
+        return lineSpacing >= lineHeight + (lineHeight >> 1); // 1.5
     }
 
     bool addSpace(const SkBounder::GlyphRec& rec)
@@ -541,9 +542,7 @@ public:
 
     virtual bool onIRect(const SkIRect& rect)
     {
-        if (top() > mBestBounds.fTop)
-            return false;
-        if (top() < mBestBounds.fTop || rect.fLeft < mBestBounds.fLeft)
+        if (mBestBounds.isEmpty())
             mBestBounds.set(rect.fLeft, top(), rect.fRight, bottom());
         return false;
     }
@@ -564,10 +563,7 @@ public:
 
     virtual bool onIRect(const SkIRect& rect)
     {
-        if (bottom() < mBestBounds.fBottom)
-            return false;
-        if (bottom() > mBestBounds.fBottom || rect.fRight > mBestBounds.fRight)
-            mBestBounds.set(rect.fLeft, top(), rect.fRight, bottom());
+        mBestBounds.set(rect.fLeft, top(), rect.fRight, bottom());
         return false;
     }
 
@@ -633,9 +629,11 @@ private:
 
 class TextExtractor : public CommonCheck {
 public:
-    TextExtractor(const SkRegion& region, const SkIRect& area)
+    TextExtractor(const SkIRect& start, const SkIRect& end, const SkIRect& area)
         : INHERITED(area.width(), area.height())
-        , mSelectRegion(region)
+        , mRecord(false)
+        , mSelectEnd(end)
+        , mSelectStart(start)
         , mSkipFirstSpace(true) // don't start with a space
     {
     }
@@ -645,7 +643,9 @@ public:
     {
         SkIRect full;
         full.set(rect.fLeft, top(), rect.fRight, bottom());
-        if (mSelectRegion.contains(full)) {
+        if (full == mSelectStart)
+            mRecord = true;
+        if (mRecord) {
             if (!mSkipFirstSpace) {
                 if (addNewLine(rec)) {
                     DBG_NAV_LOG("write new line");
@@ -675,6 +675,8 @@ public:
             DBG_NAV_LOGD("TextExtractor [%02x] skip full=(%d,%d,r=%d,b=%d)",
                 rec.fGlyphID, full.fLeft, full.fTop, full.fRight, full.fBottom);
         }
+        if (full == mSelectEnd)
+            mRecord = false;
         return false;
     }
 
@@ -696,7 +698,9 @@ public:
     }
 
 protected:
-    const SkRegion& mSelectRegion;
+    bool mRecord;
+    const SkIRect& mSelectEnd;
+    const SkIRect& mSelectStart;
     SkTDArray<uint16_t> mSelectText;
     bool mSkipFirstSpace;
 private:
@@ -865,15 +869,9 @@ static SkIRect findRight(const SkPicture& picture, const SkIRect& area,
 }
 
 static WebCore::String text(const SkPicture& picture, const SkIRect& area,
-        const SkRegion& region)
+        const SkIRect& start, const SkIRect& end)
 {
-    SkRegion copy = region;
-    copy.translate(-area.fLeft, -area.fTop);
-    const SkIRect& bounds = copy.getBounds();
-    DBG_NAV_LOGD("area=(%d, %d, %d, %d) region=(%d, %d, %d, %d)",
-        area.fLeft, area.fTop, area.fRight, area.fBottom,
-        bounds.fLeft, bounds.fTop, bounds.fRight, bounds.fBottom);
-    TextExtractor extractor(copy, area);
+    TextExtractor extractor(start, end, area);
     TextCanvas checker(&extractor, area);
     checker.drawPicture(const_cast<SkPicture&>(picture));
     return extractor.text();
@@ -1063,10 +1061,14 @@ void SelectText::extendSelection(const SkPicture* picture, int x, int y)
 
 const String SelectText::getSelection()
 {
-    SkIRect clipRect = m_selRegion.getBounds();
-    DBG_NAV_LOGD("clip=(%d,%d,%d,%d)", clipRect.fLeft,
-        clipRect.fTop, clipRect.fRight, clipRect.fBottom);
-    String result = text(*m_picture, clipRect, m_selRegion);
+    SkIRect clipRect;
+    clipRect.set(0, 0, m_picture->width(), m_picture->height());
+    String result = text(*m_picture, clipRect, m_selStart, m_selEnd);
+    DBG_NAV_LOGD("clip=(%d,%d,%d,%d)"
+        " m_selStart=(%d, %d, %d, %d) m_selEnd=(%d, %d, %d, %d)",
+        clipRect.fLeft, clipRect.fTop, clipRect.fRight, clipRect.fBottom,
+        m_selStart.fLeft, m_selStart.fTop, m_selStart.fRight, m_selStart.fBottom,
+        m_selEnd.fLeft, m_selEnd.fTop, m_selEnd.fRight, m_selEnd.fBottom);
     DBG_NAV_LOGD("text=%s", result.latin1().data()); // uses CString
     return result;
 }