Add views::RichLabel, a class which creates multi-line text with mixed

ui/views/controls/styled_label.cc

Index: ui/views/controls/styled_label.cc
diff --git a/ui/views/controls/styled_label.cc b/ui/views/controls/styled_label.cc
new file mode 100644
index 0000000000000000000000000000000000000000..b04be762828fb0d8d81c9d7c808931f32fe98fe9
--- /dev/null
+++ b/ui/views/controls/styled_label.cc
@@ -0,0 +1,143 @@
+// Copyright 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "ui/views/controls/styled_label.h"
+
+#include <vector>
+
+#include "base/string_util.h"
+#include "ui/base/resource/resource_bundle.h"
+#include "ui/base/text/text_elider.h"
+#include "ui/views/controls/label.h"
+#include "ui/views/controls/link.h"
+#include "ui/views/controls/styled_label_listener.h"
+
+namespace views {
+
+bool StyledLabel::LinkRange::operator<(const StyledLabel::LinkRange& other)
+    const {
+  // Intentionally reversed so the priority queue is sorted by smallest first.
+  return range.start() > other.range.start();
+}
+
+StyledLabel::StyledLabel(const string16& text, StyledLabelListener* listener)

[msw, 2013/03/13 03:22:07]

nit: move the 2nd arg to a new line.

[sky, 2013/03/13 14:33:00]

Not necessary. You only need put each arg on its own line if the constructor
can't fit on the same line.

+    : text_(text),
+      listener_(listener) {}
+
+StyledLabel::~StyledLabel() {}
+
+void StyledLabel::SetLink(const ui::Range& range) {
+  DCHECK(ui::Range(0, text_.size()).Contains(range));
+  link_ranges_.push(LinkRange(range));

[sky, 2013/03/13 14:33:00]

Doesn't this need to mark the calculated_size_ invalid?

[Evan Stade, 2013/03/14 00:30:46]

Done.

+}
+
+int StyledLabel::GetHeightForWidth(int w) {
+  if (w != calculated_size_.width())
+    calculated_size_ = gfx::Size(w, CalculateAndDoLayout(w, true));
+
+  return calculated_size_.height();
+}
+
+void StyledLabel::Layout() {
+  CalculateAndDoLayout(GetLocalBounds().width(), false);

[sky, 2013/03/13 14:33:00]

Honor the border here and in CalculateAndDoLayout.

[Evan Stade, 2013/03/14 00:30:46]

Done.

+}
+
+int StyledLabel::CalculateAndDoLayout(int width, bool dry_run) {
+  if (width == 0)
+    return 0;
+
+  if (!dry_run) {
+    RemoveAllChildViews(true);
+    link_targets_.clear();
+  }
+
+  gfx::Font font =
+      ResourceBundle::GetSharedInstance().GetFont(ResourceBundle::BaseFont);
+
+  int line_height = font.GetHeight();
+  // The index of the line we're on.
+  int line = 0;
+  // The x position (in pixels) of the line we're on.
+  int x = 0;
+
+  string16 remaining_string = text_;
+  std::priority_queue<LinkRange> link_ranges = link_ranges_;
+
+  // Iterate over the text, creating a bunch of labels and links and laying them
+  // out in the appropriate positions.
+  while (!remaining_string.empty()) {
+    // Don't put whitespace at beginning of a line.
+    if (x == 0)
+      TrimWhitespace(remaining_string, TRIM_LEADING, &remaining_string);
+
+    ui::Range range(ui::Range::InvalidRange());
+    if (!link_ranges.empty())
+      range = link_ranges.top().range;
+
+    gfx::Rect chunk_bounds(x, 0, width - x, 2 * line_height);
+    std::vector<string16> substrings;
+    ui::ElideRectangleText(remaining_string,
+                           font,
+                           chunk_bounds.width(),
+                           chunk_bounds.height(),
+                           ui::IGNORE_LONG_WORDS,
+                           &substrings);
+
+    string16 chunk = substrings[0];
+    if (chunk.empty()) {
+      // Nothing fit on this line. Start a new line. If x is 0, there's no room
+      // for anything. Just abort.
+      if (x == 0)
+        break;
+
+      x = 0;
+      line++;
+      continue;
+    }
+
+    scoped_ptr<View> view;
+    size_t position = text_.size() - remaining_string.size();
+    if (position >= range.start()) {
+      // This chunk is a link.
+      if (chunk.size() < range.length() && x != 0) {
+        // Don't wrap links. Try to fit them entirely on one line.
+        x = 0;
+        line++;
+        continue;
+      }
+
+      chunk = chunk.substr(0, range.length());
+      Link* link = new Link(chunk);
+      link->set_listener(this);
+      if (!dry_run)
+        link_targets_[link] = range;
+      view.reset(link);

[sky, 2013/03/13 14:33:00]

Do links have the same preferred height as labels?

[Evan Stade, 2013/03/14 00:30:46]

nope, fixed by adding a focus border (which shouldn't ever actually show, but
does affect the label's insets).

+      link_ranges.pop();
+    } else {
+      // This chunk is normal text.
+      if (position + chunk.size() > range.start())
+        chunk = chunk.substr(0, range.start() - position);
+
+      view.reset(new Label(chunk));
+    }
+
+    gfx::Size view_size = view->GetPreferredSize();
+    if (!dry_run) {
+      view->SetBoundsRect(gfx::Rect(gfx::Point(x, line * line_height),
+                                    view_size));
+      AddChildView(view.release());
+    }
+    x += view_size.width();
+
+    remaining_string = remaining_string.substr(chunk.size());
+  }
+
+  return (line + 1) * line_height;
+}
+
+void StyledLabel::LinkClicked(Link* source, int event_flags) {
+  listener_->StyledLabelLinkClicked(link_targets_[source], event_flags);
+}
+
+}  // namespace views