Windows implementation of multiline RenderText

ui/gfx/render_text.cc

Index: ui/gfx/render_text.cc
diff --git a/ui/gfx/render_text.cc b/ui/gfx/render_text.cc
index cdc706ed28193eee11213fa5154fbc1e4447a265..1c8ca71b55ed84245fe1b3262c09302a11e46f85 100644
--- a/ui/gfx/render_text.cc
+++ b/ui/gfx/render_text.cc
@@ -306,8 +306,19 @@ RenderText::~RenderText() {
 
 void RenderText::SetText(const base::string16& text) {
   DCHECK(!composition_range_.IsValid());
+  if (text_ == text)
+    return;
   text_ = text;
 
+  // TODO: we might be displaying obscured_text... also move somewhere better.

[Alexei Svitkine (slow), 2013/07/09 15:35:13]

I think this should be done at the end of UpdateLayoutText() with
GetLayoutText() as input.

[ckocagil, 2013/07/13 16:05:10]

Done.

+  line_breaks_.clear();
+  base::i18n::BreakIterator iter(text_, base::i18n::BreakIterator::BREAK_LINE);
+  bool success = iter.Init();
+  CHECK(success);
+  do {
+    line_breaks_.push_back(iter.pos());
+  } while (iter.Advance());
+
   // Adjust ranged styles and colors to accommodate a new text length.
   const size_t text_length = text_.length();
   colors_.SetMax(text_length);
@@ -397,6 +408,7 @@ void RenderText::SetObscuredRevealIndex(int index) {
 void RenderText::SetDisplayRect(const Rect& r) {
   display_rect_ = r;
   cached_bounds_and_offset_valid_ = false;
+  lines_valid_ = false;
 }
 
 void RenderText::SetCursorPosition(size_t position) {
@@ -689,18 +701,50 @@ Rect RenderText::GetCursorBounds(const SelectionModel& caret,
     // since there is nothing to overtype.
     if ((GetTextDirection() == base::i18n::RIGHT_TO_LEFT) == (caret_pos == 0))
       x = size.width();
-  } else {
-    size_t grapheme_start = (caret_affinity == CURSOR_FORWARD) ?
-        caret_pos : IndexOfAdjacentGrapheme(caret_pos, CURSOR_BACKWARD);
-    ui::Range xspan(GetGlyphBounds(grapheme_start));
-    if (insert_mode) {
-      x = (caret_affinity == CURSOR_BACKWARD) ? xspan.end() : xspan.start();
-    } else {  // overtype mode
-      x = xspan.GetMin();
-      width = xspan.length();
+  } else {
+    size_t grapheme_start = (caret_affinity == CURSOR_FORWARD) ?
+        caret_pos : IndexOfAdjacentGrapheme(caret_pos, CURSOR_BACKWARD);
+    ui::Range xspan(GetGlyphBounds(grapheme_start));
+    if (insert_mode) {
+      x = (caret_affinity == CURSOR_BACKWARD) ? xspan.end() : xspan.start();
+    } else {  // overtype mode
+      x = xspan.GetMin();
+      width = xspan.length();
+    }
+  }
+  return Rect(ToViewPoint(Point(x, 0)), Size(width, size.height()));
+}
+
+std::vector<Rect> RenderText::RangeToViewRects(const ui::Range& x, int y) {
+  std::vector<Rect> rects;
+
+  int height = GetStringSize().height();

[msw, 2013/07/10 04:01:56]

This is fine for the single line case, but each line in multi-line should have
its height computed as the max of the LineSegments' heights.

[ckocagil, 2013/07/13 16:05:10]

Done.

+
+  if (!multiline()) {
+    Point start(x.GetMin(), y);
+    rects.push_back(Rect(ToViewPoint(start), Size(x.length(), height)));
+    return rects;
+  }
+
+  EnsureLayout();
+  ComputeLines();

[msw, 2013/07/10 04:01:56]

EnsureLayout should ComputeLines as needed, don't invoke it explicitly here.

[ckocagil, 2013/07/13 16:05:10]

Done.

+
+  for (size_t line = 0; line < lines().size(); ++line) {

[msw, 2013/07/10 04:01:56]

Add a comment to explain what's happening here, it seems odd.

[ckocagil, 2013/07/13 16:05:10]

Done.

+    int line_x = 0;
+    for (size_t i = 0; i < lines()[line].size(); ++i) {
+      const internal::LineSegment* segment = lines()[line][i];
+      ui::Range intersection = segment->x_pos.Intersect(x);
+      if (!intersection.is_empty()) {
+        Rect rect(line_x + intersection.start() - segment->x_pos.start(),
+                  y + line * height, intersection.length(), height);

[msw, 2013/07/10 04:01:56]

You need to use the proper per-line heights; at least add a TODO.

[ckocagil, 2013/07/13 16:05:10]

Done, it uses per-line heights now.

+        rect += GetTextOffset(LineWidth(line));

[msw, 2013/07/10 04:01:56]

Cache the line's offset in the outer loop.

[ckocagil, 2013/07/13 16:05:10]

Done.

+        rects.push_back(rect);
+      }
+      line_x += segment->x_pos.length();
     }
   }
-  return Rect(ToViewPoint(Point(x, 0)), Size(width, size.height()));
+
+  return rects;
 }
 
 const Rect& RenderText::GetUpdatedCursorBounds() {
@@ -763,11 +807,13 @@ RenderText::RenderText()
       composition_and_selection_styles_applied_(false),
       obscured_(false),
       obscured_reveal_index_(-1),
+      multiline_(false),
       fade_head_(false),
       fade_tail_(false),
       background_is_transparent_(false),
       clip_to_display_rect_(true),
-      cached_bounds_and_offset_valid_(false) {
+      cached_bounds_and_offset_valid_(false),
+      lines_valid_(false) {
 }
 
 const Vector2d& RenderText::GetUpdatedDisplayOffset() {
@@ -832,30 +878,45 @@ void RenderText::UndoCompositionAndSelectionStyles() {
   composition_and_selection_styles_applied_ = false;
 }
 
-Vector2d RenderText::GetTextOffset() {
+Vector2d RenderText::GetTextOffset(int line_width) {
   Vector2d offset = display_rect().OffsetFromOrigin();
-  offset.Add(GetUpdatedDisplayOffset());
-  offset.Add(GetAlignmentOffset());
+  if (!multiline())

[msw, 2013/07/10 04:01:56]

Why ignore the display offset for multi-line? Eventually we'll need to be able
to scroll multi-line text too.

[ckocagil, 2013/07/13 16:05:10]

I ignored it for now because multi-line vertical scrolling requires further work
in UpdateCachedBoundsAndOffset. Added a TODO there.

+    offset.Add(GetUpdatedDisplayOffset());
+  offset.Add(GetAlignmentOffset(line_width));
   return offset;
 }
 
 Point RenderText::ToTextPoint(const Point& point) {
-  return point - GetTextOffset();
+  return point - GetTextOffset(GetContentWidth());
+  // TODO: implement multiline

[Alexei Svitkine (slow), 2013/07/09 15:35:13]

TODO(ckocagil)

[ckocagil, 2013/07/13 16:05:10]

Done.

 }
 
 Point RenderText::ToViewPoint(const Point& point) {
-  return point + GetTextOffset();
+  if (!multiline())
+    return point + GetTextOffset(GetContentWidth());
+
+  ComputeLines();

[msw, 2013/07/10 04:01:56]

Don't explicitly call this here, EnsureLayout or [D]CHECK(lines_valid_).

[ckocagil, 2013/07/13 16:05:10]

Done.

+  int x = point.x();
+  unsigned int line = 0;
+  while (line < lines_.size() && x > LineWidth(line)) {
+    x -= LineWidth(line);

[Alexei Svitkine (slow), 2013/07/09 15:35:13]

Can you refactor this code to not call LineWidth() twice per line?

[ckocagil, 2013/07/13 16:05:10]

I will rewrite this method to support RTL soon (before we land this).

+    ++line;
+  }
+  return Point(x, point.y() + line * GetStringSize().height()) +

[msw, 2013/07/10 04:01:56]

Again, this needs per-line heights.

[ckocagil, 2013/07/13 16:05:10]

Done.

+      GetTextOffset(LineWidth(line));
 }
 
-Vector2d RenderText::GetAlignmentOffset() {
+Vector2d RenderText::GetAlignmentOffset(int line_width) {
+

[msw, 2013/07/10 04:01:56]

nit: remove blank line.

[ckocagil, 2013/07/13 16:05:10]

Done.

   Vector2d offset;
   if (horizontal_alignment_ != ALIGN_LEFT) {
-    offset.set_x(display_rect().width() - GetContentWidth());
+    offset.set_x(display_rect().width() - (multiline() ? line_width

[msw, 2013/07/10 04:01:56]

Always use |line_width|, you pass in GetContentWidth() correctly.

[ckocagil, 2013/07/13 16:05:10]

I now pass 0 for single-line mode. Single-line mode will generate a Line struct
in the future and we won't need this conditional expression.

+                                                       : GetContentWidth()));
     if (horizontal_alignment_ == ALIGN_CENTER)
       offset.set_x(offset.x() / 2);
   }
   if (vertical_alignment_ != ALIGN_TOP) {
-    offset.set_y(display_rect().height() - GetStringSize().height());
+    offset.set_y(display_rect().height() - GetMultilineTextSize().height());
     if (vertical_alignment_ == ALIGN_VCENTER)
       offset.set_y(offset.y() / 2);
   }
@@ -901,7 +962,7 @@ void RenderText::ApplyFadeEffects(internal::SkiaTextRenderer* renderer) {
   }
 
   Rect text_rect = display_rect();
-  text_rect.Inset(GetAlignmentOffset().x(), 0, 0, 0);
+  text_rect.Inset(GetAlignmentOffset(GetContentWidth()).x(), 0, 0, 0);
 
   // TODO(msw): Use the actual text colors corresponding to each faded part.
   skia::RefPtr<SkShader> shader = CreateFadeShader(