Clean up/simplify StyledLabel, part 3.

* Convert the central loop of CalculateAndDoLayout() to two nested loops.  The
  outer loop iterates once per line, the inner once per view.  This allows
  unifying all existing calls to AdvanceOneLine() to a single one in the outer
  loop.
* At this point AdvanceOneLine() can be inlined and simplified.

Bug: 1015717
Change-Id: Iecd4832a7b8eafccd69b50a7951628fded1336f4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1874825
Commit-Queue: Peter Kasting <pkasting@chromium.org>
Auto-Submit: Peter Kasting <pkasting@chromium.org>
Reviewed-by: Trent Apted <tapted@chromium.org>
Cr-Commit-Position: refs/heads/master@{#708844}

ui/views/controls/styled_label.cc

@@ -321,7 +321,7 @@ gfx::Size StyledLabel::CalculateAndDoLayout(int width, bool dry_run) {
 
   // Iterate over the text, creating a bunch of labels and links and laying them
   // out in the appropriate positions.
-  {
+  while (!remaining_string.empty()) {
     // Max height of the views in a line.
     int line_height = default_line_height;
 
@@ -369,11 +369,14 @@ gfx::Size StyledLabel::CalculateAndDoLayout(int width, bool dry_run) {
             chunk_bounds.height(), gfx::WRAP_LONG_WORDS, &substrings);
 
         if (substrings.empty()) {
-          // There is no room for anything; abort. Since wrapping is enabled,
-          // this should only occur if there is insufficient vertical space
-          // remaining. ElideRectangleText always adds a single character, even
-          // if there is no room horizontally.
+          // There is no room for anything. Since wrapping is enabled, this
+          // should only occur if there is insufficient vertical space
+          // remaining. ElideRectangleText() always adds a single character,
+          // even if there is no room horizontally.
           DCHECK_NE(0, elide_result & gfx::INSUFFICIENT_SPACE_VERTICAL);
+          // There's no way to continue processing; clear |remaining_string| so
+          // the outer loop will terminate after this iteration completes.
+          remaining_string.clear();
           break;
         }
 
@@ -393,8 +396,7 @@ gfx::Size StyledLabel::CalculateAndDoLayout(int width, bool dry_run) {
           // line. As for the first line, don't advance line number so that it
           // will be handled again at the beginning of the loop.
           if (offset.x() != 0 || line > 0)
-            AdvanceOneLine(&line, &offset, &line_height, width,
-                           &views_in_a_line);
+            break;
           DCHECK(views_in_a_line.empty());
           continue;
         }
@@ -428,8 +430,7 @@ gfx::Size StyledLabel::CalculateAndDoLayout(int width, bool dry_run) {
             position == range.start() && offset.x() != 0) {
           // If the chunk should not be wrapped, try to fit it entirely on the
           // next line.
-          AdvanceOneLine(&line, &offset, &line_height, width, &views_in_a_line);
-          continue;
+          break;
         }
 
         if (chunk.size() > range.end() - position)
@@ -489,36 +490,28 @@ gfx::Size StyledLabel::CalculateAndDoLayout(int width, bool dry_run) {
       // substring has different style), proceed to the next line.
       if (!custom_view && substrings.size() > 1 &&
           chunk.size() == substrings[0].size()) {
-        AdvanceOneLine(&line, &offset, &line_height, width, &views_in_a_line);
+        break;
       }
     }
-    AdvanceOneLine(&line, &offset, &line_height, width, &views_in_a_line);
+
+    // Adjust the positions of the views in the line.
+    const int x_delta =
+        HorizontalAdjustment(offset.x(), width, horizontal_alignment_);
+    for (auto* view : views_in_a_line) {
+      view->SetPosition({view->x() + x_delta,
+                         offset.y() + (line_height - view->height()) / 2.0f});
+    }
+
+    // Move to the next line.
+    ++line;
+    offset = gfx::Point(0, offset.y() + line_height);
   }
+
   DCHECK_LE(used_width, width);
   calculated_size_ = gfx::Size(used_width + GetInsets().width(), total_height);
   return calculated_size_;
 }
 
-void StyledLabel::AdvanceOneLine(int* line_number,
-                                 gfx::Point* offset,
-                                 int* line_height,
-                                 int width,
-                                 std::vector<View*>* views_in_a_line) {
-  const int x_delta =
-      HorizontalAdjustment(offset->x(), width, horizontal_alignment_);
-  for (auto* view : *views_in_a_line) {
-    gfx::Rect bounds = view->bounds();
-    bounds.set_x(bounds.x() + x_delta);
-    bounds.set_y(offset->y() + (*line_height - bounds.height()) / 2.0f);
-    view->SetBoundsRect(bounds);
-  }
-  views_in_a_line->clear();
-
-  ++(*line_number);
-  *offset = gfx::Point(0, offset->y() + *line_height);
-  *line_height = GetDefaultLineHeight();
-}
-
 std::unique_ptr<Label> StyledLabel::CreateLabel(
     const base::string16& text,
     const StyledLabel::RangeStyleInfo& style_info) const {

ui/views/controls/styled_label.h

@@ -187,14 +187,6 @@ class VIEWS_EXPORT StyledLabel : public View, public LinkListener {
   std::unique_ptr<Label> CreateLabel(const base::string16& text,
                                      const RangeStyleInfo& style_info) const;
 
-  // Adjusts the offsets of the views in a line for alignment and other line
-  // parameters.
-  void AdvanceOneLine(int* line_number,
-                      gfx::Point* offset,
-                      int* max_line_height,
-                      int width,
-                      std::vector<View*>* views_in_a_line);
-
   // The text to display.
   base::string16 text_;