ozone: Allow building for ozone without depending on pango

ui/gfx/render_text_linux.cc

Index: ui/gfx/render_text_linux.cc
diff --git a/ui/gfx/render_text_linux.cc b/ui/gfx/render_text_linux.cc
deleted file mode 100644
index 3166875758b65568c7a83d99c403e85097c34f3c..0000000000000000000000000000000000000000
--- a/ui/gfx/render_text_linux.cc
+++ /dev/null
@@ -1,514 +0,0 @@
-// Copyright (c) 2012 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/gfx/render_text_linux.h"
-
-#include <pango/pangocairo.h>
-#include <algorithm>
-#include <string>
-#include <vector>
-
-#include "base/i18n/break_iterator.h"
-#include "base/logging.h"
-#include "third_party/skia/include/core/SkTypeface.h"
-#include "ui/gfx/canvas.h"
-#include "ui/gfx/font.h"
-#include "ui/gfx/font_render_params_linux.h"
-#include "ui/gfx/pango_util.h"
-#include "ui/gfx/utf16_indexing.h"
-
-namespace gfx {
-
-namespace {
-
-// Returns the preceding element in a GSList (O(n)).
-GSList* GSListPrevious(GSList* head, GSList* item) {
-  GSList* prev = NULL;
-  for (GSList* cur = head; cur != item; cur = cur->next) {
-    DCHECK(cur);
-    prev = cur;
-  }
-  return prev;
-}
-
-// Returns true if the given visual cursor |direction| is logically forward
-// motion in the given Pango |item|.
-bool IsForwardMotion(VisualCursorDirection direction, const PangoItem* item) {
-  bool rtl = item->analysis.level & 1;
-  return rtl == (direction == CURSOR_LEFT);
-}
-
-// Checks whether |range| contains |index|. This is not the same as calling
-// |range.Contains(gfx::Range(index))| - as that would return true when
-// |index| == |range.end()|.
-bool IndexInRange(const Range& range, size_t index) {
-  return index >= range.start() && index < range.end();
-}
-
-// Sets underline metrics on |renderer| according to Pango font |desc|.
-void SetPangoUnderlineMetrics(PangoFontDescription *desc,
-                              internal::SkiaTextRenderer* renderer) {
-  PangoFontMetrics* metrics = GetPangoFontMetrics(desc);
-  int thickness = pango_font_metrics_get_underline_thickness(metrics);
-  // Pango returns the position "above the baseline". Change its sign to convert
-  // it to a vertical offset from the baseline.
-  int position = -pango_font_metrics_get_underline_position(metrics);
-  pango_quantize_line_geometry(&thickness, &position);
-  // Note: pango_quantize_line_geometry() guarantees pixel boundaries, so
-  //       PANGO_PIXELS() is safe to use.
-  renderer->SetUnderlineMetrics(PANGO_PIXELS(thickness),
-                                PANGO_PIXELS(position));
-}
-
-}  // namespace
-
-// TODO(xji): index saved in upper layer is utf16 index. Pango uses utf8 index.
-// Since caret_pos is used internally, we could save utf8 index for caret_pos
-// to avoid conversion.
-
-RenderTextLinux::RenderTextLinux()
-    : layout_(NULL),
-      current_line_(NULL),
-      log_attrs_(NULL),
-      num_log_attrs_(0),
-      layout_text_(NULL) {
-}
-
-RenderTextLinux::~RenderTextLinux() {
-  ResetLayout();
-}
-
-Size RenderTextLinux::GetStringSize() {
-  EnsureLayout();
-  int width = 0, height = 0;
-  pango_layout_get_pixel_size(layout_, &width, &height);
-  // Keep a consistent height between this particular string's PangoLayout and
-  // potentially larger text supported by the FontList.
-  // For example, if a text field contains a Japanese character, which is
-  // smaller than Latin ones, and then later a Latin one is inserted, this
-  // ensures that the text baseline does not shift.
-  return Size(width, std::max(height, font_list().GetHeight()));
-}
-
-SelectionModel RenderTextLinux::FindCursorPosition(const Point& point) {
-  EnsureLayout();
-
-  if (text().empty())
-    return SelectionModel(0, CURSOR_FORWARD);
-
-  Point p(ToTextPoint(point));
-
-  // When the point is outside of text, return HOME/END position.
-  if (p.x() < 0)
-    return EdgeSelectionModel(CURSOR_LEFT);
-  if (p.x() > GetStringSize().width())
-    return EdgeSelectionModel(CURSOR_RIGHT);
-
-  int caret_pos = 0, trailing = 0;
-  pango_layout_xy_to_index(layout_, p.x() * PANGO_SCALE, p.y() * PANGO_SCALE,
-                           &caret_pos, &trailing);
-
-  DCHECK_GE(trailing, 0);
-  if (trailing > 0) {
-    caret_pos = g_utf8_offset_to_pointer(layout_text_ + caret_pos,
-                                         trailing) - layout_text_;
-    DCHECK_LE(static_cast<size_t>(caret_pos), strlen(layout_text_));
-  }
-
-  return SelectionModel(LayoutIndexToTextIndex(caret_pos),
-                        (trailing > 0) ? CURSOR_BACKWARD : CURSOR_FORWARD);
-}
-
-std::vector<RenderText::FontSpan> RenderTextLinux::GetFontSpansForTesting() {
-  EnsureLayout();
-
-  std::vector<RenderText::FontSpan> spans;
-  for (GSList* it = current_line_->runs; it; it = it->next) {
-    PangoItem* item = reinterpret_cast<PangoLayoutRun*>(it->data)->item;
-    const int start = LayoutIndexToTextIndex(item->offset);
-    const int end = LayoutIndexToTextIndex(item->offset + item->length);
-    const Range range(start, end);
-
-    ScopedPangoFontDescription desc(pango_font_describe(item->analysis.font));
-    spans.push_back(RenderText::FontSpan(Font(desc.get()), range));
-  }
-
-  return spans;
-}
-
-int RenderTextLinux::GetLayoutTextBaseline() {
-  EnsureLayout();
-  return PANGO_PIXELS(pango_layout_get_baseline(layout_));
-}
-
-SelectionModel RenderTextLinux::AdjacentCharSelectionModel(
-    const SelectionModel& selection,
-    VisualCursorDirection direction) {
-  GSList* run = GetRunContainingCaret(selection);
-  if (!run) {
-    // The cursor is not in any run: we're at the visual and logical edge.
-    SelectionModel edge = EdgeSelectionModel(direction);
-    if (edge.caret_pos() == selection.caret_pos())
-      return edge;
-    else
-      run = (direction == CURSOR_RIGHT) ?
-          current_line_->runs : g_slist_last(current_line_->runs);
-  } else {
-    // If the cursor is moving within the current run, just move it by one
-    // grapheme in the appropriate direction.
-    PangoItem* item = reinterpret_cast<PangoLayoutRun*>(run->data)->item;
-    size_t caret = selection.caret_pos();
-    if (IsForwardMotion(direction, item)) {
-      if (caret < LayoutIndexToTextIndex(item->offset + item->length)) {
-        caret = IndexOfAdjacentGrapheme(caret, CURSOR_FORWARD);
-        return SelectionModel(caret, CURSOR_BACKWARD);
-      }
-    } else {
-      if (caret > LayoutIndexToTextIndex(item->offset)) {
-        caret = IndexOfAdjacentGrapheme(caret, CURSOR_BACKWARD);
-        return SelectionModel(caret, CURSOR_FORWARD);
-      }
-    }
-    // The cursor is at the edge of a run; move to the visually adjacent run.
-    // TODO(xji): Keep a vector of runs to avoid using a singly-linked list.
-    run = (direction == CURSOR_RIGHT) ?
-        run->next : GSListPrevious(current_line_->runs, run);
-    if (!run)
-      return EdgeSelectionModel(direction);
-  }
-  PangoItem* item = reinterpret_cast<PangoLayoutRun*>(run->data)->item;
-  return IsForwardMotion(direction, item) ?
-      FirstSelectionModelInsideRun(item) : LastSelectionModelInsideRun(item);
-}
-
-SelectionModel RenderTextLinux::AdjacentWordSelectionModel(
-    const SelectionModel& selection,
-    VisualCursorDirection direction) {
-  if (obscured())
-    return EdgeSelectionModel(direction);
-
-  base::i18n::BreakIterator iter(text(), base::i18n::BreakIterator::BREAK_WORD);
-  bool success = iter.Init();
-  DCHECK(success);
-  if (!success)
-    return selection;
-
-  SelectionModel cur(selection);
-  for (;;) {
-    cur = AdjacentCharSelectionModel(cur, direction);
-    GSList* run = GetRunContainingCaret(cur);
-    if (!run)
-      break;
-    PangoItem* item = reinterpret_cast<PangoLayoutRun*>(run->data)->item;
-    size_t cursor = cur.caret_pos();
-    if (IsForwardMotion(direction, item) ?
-        iter.IsEndOfWord(cursor) : iter.IsStartOfWord(cursor))
-      break;
-  }
-
-  return cur;
-}
-
-Range RenderTextLinux::GetGlyphBounds(size_t index) {
-  PangoRectangle pos;
-  pango_layout_index_to_pos(layout_, TextIndexToLayoutIndex(index), &pos);
-  // TODO(derat): Support fractional ranges for subpixel positioning?
-  return Range(PANGO_PIXELS(pos.x), PANGO_PIXELS(pos.x + pos.width));
-}
-
-std::vector<Rect> RenderTextLinux::GetSubstringBounds(const Range& range) {
-  DCHECK_LE(range.GetMax(), text().length());
-  if (range.is_empty())
-    return std::vector<Rect>();
-
-  EnsureLayout();
-  int* ranges = NULL;
-  int n_ranges = 0;
-  pango_layout_line_get_x_ranges(current_line_,
-                                 TextIndexToLayoutIndex(range.GetMin()),
-                                 TextIndexToLayoutIndex(range.GetMax()),
-                                 &ranges,
-                                 &n_ranges);
-
-  const int height = GetStringSize().height();
-
-  std::vector<Rect> bounds;
-  for (int i = 0; i < n_ranges; ++i) {
-    // TODO(derat): Support fractional bounds for subpixel positioning?
-    int x = PANGO_PIXELS(ranges[2 * i]);
-    int width = PANGO_PIXELS(ranges[2 * i + 1]) - x;
-    Rect rect(x, 0, width, height);
-    rect.set_origin(ToViewPoint(rect.origin()));
-    bounds.push_back(rect);
-  }
-  g_free(ranges);
-  return bounds;
-}
-
-size_t RenderTextLinux::TextIndexToLayoutIndex(size_t index) const {
-  DCHECK(layout_);
-  ptrdiff_t offset = gfx::UTF16IndexToOffset(text(), 0, index);
-  // Clamp layout indices to the length of the text actually used for layout.
-  offset = std::min<size_t>(offset, g_utf8_strlen(layout_text_, -1));
-  const char* layout_pointer = g_utf8_offset_to_pointer(layout_text_, offset);
-  return (layout_pointer - layout_text_);
-}
-
-size_t RenderTextLinux::LayoutIndexToTextIndex(size_t index) const {
-  DCHECK(layout_);
-  const char* layout_pointer = layout_text_ + index;
-  const long offset = g_utf8_pointer_to_offset(layout_text_, layout_pointer);
-  return gfx::UTF16OffsetToIndex(text(), 0, offset);
-}
-
-bool RenderTextLinux::IsCursorablePosition(size_t position) {
-  if (position == 0 && text().empty())
-    return true;
-  if (position >= text().length())
-    return position == text().length();
-  if (!gfx::IsValidCodePointIndex(text(), position))
-    return false;
-
-  EnsureLayout();
-  ptrdiff_t offset = gfx::UTF16IndexToOffset(text(), 0, position);
-  // Check that the index corresponds with a valid text code point, that it is
-  // marked as a legitimate cursor position by Pango, and that it is not
-  // truncated from layout text (its glyph is shown on screen).
-  return (offset < num_log_attrs_ && log_attrs_[offset].is_cursor_position &&
-          offset < g_utf8_strlen(layout_text_, -1));
-}
-
-void RenderTextLinux::ResetLayout() {
-  // set_cached_bounds_and_offset_valid(false) is done in RenderText for every
-  // operation that triggers ResetLayout().
-  if (layout_) {
-    // TODO(msw): Keep |layout_| across text changes, etc.; it can be re-used.
-    g_object_unref(layout_);
-    layout_ = NULL;
-  }
-  if (current_line_) {
-    pango_layout_line_unref(current_line_);
-    current_line_ = NULL;
-  }
-  if (log_attrs_) {
-    g_free(log_attrs_);
-    log_attrs_ = NULL;
-    num_log_attrs_ = 0;
-  }
-  layout_text_ = NULL;
-}
-
-void RenderTextLinux::EnsureLayout() {
-  if (layout_ == NULL) {
-    cairo_surface_t* surface =
-        cairo_image_surface_create(CAIRO_FORMAT_ARGB32, 0, 0);
-    CHECK_EQ(CAIRO_STATUS_SUCCESS, cairo_surface_status(surface));
-    cairo_t* cr = cairo_create(surface);
-    CHECK_EQ(CAIRO_STATUS_SUCCESS, cairo_status(cr));
-
-    layout_ = pango_cairo_create_layout(cr);
-    CHECK_NE(static_cast<PangoLayout*>(NULL), layout_);
-    cairo_destroy(cr);
-    cairo_surface_destroy(surface);
-
-    SetupPangoLayoutWithFontDescription(layout_,
-                                        GetLayoutText(),
-                                        font_list().GetFontDescriptionString(),
-                                        0,
-                                        GetTextDirection(),
-                                        Canvas::DefaultCanvasTextAlignment());
-
-    // No width set so that the x-axis position is relative to the start of the
-    // text. ToViewPoint and ToTextPoint take care of the position conversion
-    // between text space and view spaces.
-    pango_layout_set_width(layout_, -1);
-    // TODO(xji): If RenderText will be used for displaying purpose, such as
-    // label, we will need to remove the single-line-mode setting.
-    pango_layout_set_single_paragraph_mode(layout_, true);
-
-    layout_text_ = pango_layout_get_text(layout_);
-    SetupPangoAttributes(layout_);
-
-    current_line_ = pango_layout_get_line_readonly(layout_, 0);
-    CHECK_NE(static_cast<PangoLayoutLine*>(NULL), current_line_);
-    pango_layout_line_ref(current_line_);
-
-    pango_layout_get_log_attrs(layout_, &log_attrs_, &num_log_attrs_);
-  }
-}
-
-void RenderTextLinux::SetupPangoAttributes(PangoLayout* layout) {
-  PangoAttrList* attrs = pango_attr_list_new();
-
-  // Splitting text runs to accommodate styling can break Arabic glyph shaping.
-  // Only split text runs as needed for bold and italic font styles changes.
-  BreakList<bool>::const_iterator bold = styles()[BOLD].breaks().begin();
-  BreakList<bool>::const_iterator italic = styles()[ITALIC].breaks().begin();
-  while (bold != styles()[BOLD].breaks().end() &&
-         italic != styles()[ITALIC].breaks().end()) {
-    const int style = (bold->second ? Font::BOLD : 0) |
-                      (italic->second ? Font::ITALIC : 0);
-    const size_t bold_end = styles()[BOLD].GetRange(bold).end();
-    const size_t italic_end = styles()[ITALIC].GetRange(italic).end();
-    const size_t style_end = std::min(bold_end, italic_end);
-    if (style != font_list().GetFontStyle()) {
-      FontList derived_font_list = font_list().DeriveFontList(style);
-      ScopedPangoFontDescription desc(pango_font_description_from_string(
-          derived_font_list.GetFontDescriptionString().c_str()));
-
-      PangoAttribute* pango_attr = pango_attr_font_desc_new(desc.get());
-      pango_attr->start_index =
-          TextIndexToLayoutIndex(std::max(bold->first, italic->first));
-      pango_attr->end_index = TextIndexToLayoutIndex(style_end);
-      pango_attr_list_insert(attrs, pango_attr);
-    }
-    bold += bold_end == style_end ? 1 : 0;
-    italic += italic_end == style_end ? 1 : 0;
-  }
-  DCHECK(bold == styles()[BOLD].breaks().end());
-  DCHECK(italic == styles()[ITALIC].breaks().end());
-
-  pango_layout_set_attributes(layout, attrs);
-  pango_attr_list_unref(attrs);
-}
-
-void RenderTextLinux::DrawVisualText(Canvas* canvas) {
-  DCHECK(layout_);
-
-  // Skia will draw glyphs with respect to the baseline.
-  Vector2d offset(GetLineOffset(0) + Vector2d(0, GetLayoutTextBaseline()));
-
-  SkScalar x = SkIntToScalar(offset.x());
-  SkScalar y = SkIntToScalar(offset.y());
-
-  std::vector<SkPoint> pos;
-  std::vector<uint16> glyphs;
-
-  internal::SkiaTextRenderer renderer(canvas);
-  ApplyFadeEffects(&renderer);
-  ApplyTextShadows(&renderer);
-
-  // TODO(derat): Use font-specific params: http://crbug.com/125235
-  const gfx::FontRenderParams& render_params =
-      gfx::GetDefaultFontRenderParams();
-  const bool use_subpixel_rendering =
-      render_params.subpixel_rendering !=
-          gfx::FontRenderParams::SUBPIXEL_RENDERING_NONE;
-  renderer.SetFontSmoothingSettings(
-      render_params.antialiasing,
-      use_subpixel_rendering && !background_is_transparent());
-
-  // Temporarily apply composition underlines and selection colors.
-  ApplyCompositionAndSelectionStyles();
-
-  internal::StyleIterator style(colors(), styles());
-  for (GSList* it = current_line_->runs; it; it = it->next) {
-    PangoLayoutRun* run = reinterpret_cast<PangoLayoutRun*>(it->data);
-    int glyph_count = run->glyphs->num_glyphs;
-    // TODO(msw): Skip painting runs outside the display rect area, like Win.
-    if (glyph_count == 0)
-      continue;
-
-    ScopedPangoFontDescription desc(
-        pango_font_describe(run->item->analysis.font));
-
-    const std::string family_name =
-        pango_font_description_get_family(desc.get());
-    renderer.SetTextSize(GetPangoFontSizeInPixels(desc.get()));
-
-    glyphs.resize(glyph_count);
-    pos.resize(glyph_count);
-
-    // Track the current glyph and the glyph at the start of its styled range.
-    int glyph_index = 0;
-    int style_start_glyph_index = glyph_index;
-
-    // Track the x-coordinates for each styled range (|x| marks the current).
-    SkScalar style_start_x = x;
-
-    // Track the current style and its text (not layout) index range.
-    style.UpdatePosition(GetGlyphTextIndex(run, style_start_glyph_index));
-    Range style_range = style.GetRange();
-
-    do {
-      const PangoGlyphInfo& glyph = run->glyphs->glyphs[glyph_index];
-      glyphs[glyph_index] = static_cast<uint16>(glyph.glyph);
-      // Use pango_units_to_double() rather than PANGO_PIXELS() here, so units
-      // are not rounded to the pixel grid if subpixel positioning is enabled.
-      pos[glyph_index].set(x + pango_units_to_double(glyph.geometry.x_offset),
-                           y + pango_units_to_double(glyph.geometry.y_offset));
-      x += pango_units_to_double(glyph.geometry.width);
-
-      ++glyph_index;
-      const size_t glyph_text_index = (glyph_index == glyph_count) ?
-          style_range.end() : GetGlyphTextIndex(run, glyph_index);
-      if (!IndexInRange(style_range, glyph_text_index)) {
-        // TODO(asvitkine): For cases like "fi", where "fi" is a single glyph
-        //                  but can span multiple styles, Pango splits the
-        //                  styles evenly over the glyph. We can do this too by
-        //                  clipping and drawing the glyph several times.
-        renderer.SetForegroundColor(style.color());
-        const int font_style = (style.style(BOLD) ? Font::BOLD : 0) |
-                               (style.style(ITALIC) ? Font::ITALIC : 0);
-        renderer.SetFontFamilyWithStyle(family_name, font_style);
-        renderer.DrawPosText(&pos[style_start_glyph_index],
-                             &glyphs[style_start_glyph_index],
-                             glyph_index - style_start_glyph_index);
-        if (style.style(UNDERLINE))
-          SetPangoUnderlineMetrics(desc.get(), &renderer);
-        renderer.DrawDecorations(style_start_x, y, x - style_start_x,
-                                 style.style(UNDERLINE), style.style(STRIKE),
-                                 style.style(DIAGONAL_STRIKE));
-        style.UpdatePosition(glyph_text_index);
-        style_range = style.GetRange();
-        style_start_glyph_index = glyph_index;
-        style_start_x = x;
-      }
-    } while (glyph_index < glyph_count);
-  }
-
-  // Undo the temporarily applied composition underlines and selection colors.
-  UndoCompositionAndSelectionStyles();
-}
-
-GSList* RenderTextLinux::GetRunContainingCaret(
-    const SelectionModel& caret) const {
-  size_t position = TextIndexToLayoutIndex(caret.caret_pos());
-  LogicalCursorDirection affinity = caret.caret_affinity();
-  GSList* run = current_line_->runs;
-  while (run) {
-    PangoItem* item = reinterpret_cast<PangoLayoutRun*>(run->data)->item;
-    Range item_range(item->offset, item->offset + item->length);
-    if (RangeContainsCaret(item_range, position, affinity))
-      return run;
-    run = run->next;
-  }
-  return NULL;
-}
-
-SelectionModel RenderTextLinux::FirstSelectionModelInsideRun(
-    const PangoItem* item) {
-  size_t caret = IndexOfAdjacentGrapheme(
-      LayoutIndexToTextIndex(item->offset), CURSOR_FORWARD);
-  return SelectionModel(caret, CURSOR_BACKWARD);
-}
-
-SelectionModel RenderTextLinux::LastSelectionModelInsideRun(
-    const PangoItem* item) {
-  size_t caret = IndexOfAdjacentGrapheme(
-      LayoutIndexToTextIndex(item->offset + item->length), CURSOR_BACKWARD);
-  return SelectionModel(caret, CURSOR_FORWARD);
-}
-
-size_t RenderTextLinux::GetGlyphTextIndex(PangoLayoutRun* run,
-                                          int glyph_index) const {
-  return LayoutIndexToTextIndex(run->item->offset +
-                                run->glyphs->log_clusters[glyph_index]);
-}
-
-RenderText* RenderText::CreateInstance() {
-  return new RenderTextLinux;
-}
-
-}  // namespace gfx