Modify candidate window to adjust shortcut and candidate column width.

* This patch is extracted from the patch (http://codereview.chromium.org/3304002/show)

Candidate window created shortcut and candidate columns in variable width,
so these columns were not aligned.

In this patch, candidate window computes column width and creates columns
in fixed width.

BUG=chromium-os:6377
TEST=manual

Review URL: http://codereview.chromium.org/3412002
Patch from Hiroki Nakagawa <nhiroki@google.com>.

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@59356 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 252 insertions, 117 deletions

diff --git a/chrome/browser/chromeos/input_method/candidate_window.cc b/chrome/browser/chromeos/input_method/candidate_window.cc
index 25049a0..78ac272 100644
--- a/chrome/browser/chromeos/input_method/candidate_window.cc
+++ b/chrome/browser/chromeos/input_method/candidate_window.cc
@@ -58,6 +58,10 @@ const SkColor kFooterBottomColor = SkColorSetRGB(0xee, 0xee, 0xee);
 const SkColor kShortcutColor = SkColorSetRGB(0x61, 0x61, 0x61);
 const SkColor kDisabledShortcutColor = SkColorSetRGB(0xcc, 0xcc, 0xcc);
 
+// We'll use a bigger font size, so Chinese characters are more readable
+// in the candidate window.
+const int kFontSizeDelta = 2;  // Two size bigger.
+
 // The minimum width of candidate labels in the vertical candidate
 // window. We use this value to prevent the candidate window from being
 // too narrow when all candidates are short.
@@ -67,6 +71,29 @@ const int kMinCandidateLabelWidth = 100;
 // too wide when one of candidates are long.
 const int kMaxCandidateLabelWidth = 500;
 
+// VerticalCandidateLabel is used for rendering candidate text in
+// the vertical candidate window.
+class VerticalCandidateLabel : public views::Label {
+  virtual ~VerticalCandidateLabel() {}
+
+  // Returns the preferred size, but guarantees that the width has at
+  // least kMinCandidateLabelWidth pixels.
+  virtual gfx::Size GetPreferredSize() {
+    gfx::Size size = Label::GetPreferredSize();
+    // Hack. +2 is needed to prevent labels from getting elided like
+    // "abc..." in some cases. TODO(satorux): Figure out why it's
+    // necessary.
+    size.set_width(size.width() + 2);
+    if (size.width() < kMinCandidateLabelWidth) {
+      size.set_width(kMinCandidateLabelWidth);
+    }
+    if (size.width() > kMaxCandidateLabelWidth) {
+      size.set_width(kMaxCandidateLabelWidth);
+    }
+    return size;
+  }
+};
+
 // Wraps the given view with some padding, and returns it.
 views::View* WrapWithPadding(views::View* view, const gfx::Insets& insets) {
   views::View* wrapper = new views::View;
@@ -86,6 +113,150 @@ views::View* WrapWithPadding(views::View* view, const gfx::Insets& insets) {
   return wrapper;
 }
 
+// Creates shortcut text from the given index and the orientation.
+std::wstring CreateShortcutText(int index,
+    chromeos::InputMethodLookupTable::Orientation orientation) {
+  // Choose the character used for the shortcut label.
+  const wchar_t kShortcutCharacters[] = L"1234567890ABCDEF";
+  // The default character should not be used but just in case.
+  wchar_t shortcut_character = L'?';
+  // -1 to exclude the null character at the end.
+  if (index < static_cast<int>(arraysize(kShortcutCharacters) - 1)) {
+    shortcut_character = kShortcutCharacters[index];
+  }
+
+  std::wstring shortcut_text;
+  if (orientation == chromeos::InputMethodLookupTable::kVertical) {
+    shortcut_text = base::StringPrintf(L"%lc", shortcut_character);
+  } else {
+    shortcut_text = base::StringPrintf(L"%lc.", shortcut_character);
+  }
+
+  return shortcut_text;
+}
+
+// Creates the shortcut label, and returns it (never returns NULL).
+// The label text is not set in this function.
+views::Label* CreateShortcutLabel(
+    chromeos::InputMethodLookupTable::Orientation orientation) {
+  // Create the shortcut label. The label will be owned by
+  // |wrapped_shortcut_label|, hence it's deleted when
+  // |wrapped_shortcut_label| is deleted.
+  views::Label* shortcut_label = new views::Label;
+
+  if (orientation == chromeos::InputMethodLookupTable::kVertical) {
+    shortcut_label->SetFont(
+        shortcut_label->font().DeriveFont(kFontSizeDelta, gfx::Font::BOLD));
+  } else {
+    shortcut_label->SetFont(
+        shortcut_label->font().DeriveFont(kFontSizeDelta));
+  }
+  // TODO(satorux): Maybe we need to use language specific fonts for
+  // candidate_label, like Chinese font for Chinese input method?
+  shortcut_label->SetColor(kShortcutColor);
+
+  return shortcut_label;
+}
+
+// Wraps the shortcut label, then decorates wrapped shortcut label
+// and returns it (never returns NULL).
+// The label text is not set in this function.
+views::View* CreateWrappedShortcutLabel(views::Label* shortcut_label,
+    chromeos::InputMethodLookupTable::Orientation orientation) {
+  // Wrap it with padding.
+  const gfx::Insets kVerticalShortcutLabelInsets(1, 6, 1, 6);
+  const gfx::Insets kHorizontalShortcutLabelInsets(1, 3, 1, 0);
+  const gfx::Insets insets =
+      (orientation == chromeos::InputMethodLookupTable::kVertical ?
+       kVerticalShortcutLabelInsets :
+       kHorizontalShortcutLabelInsets);
+  views::View* wrapped_shortcut_label =
+      WrapWithPadding(shortcut_label, insets);
+
+  // Add decoration based on the orientation.
+  if (orientation == chromeos::InputMethodLookupTable::kVertical) {
+    // Set the background color.
+    wrapped_shortcut_label->set_background(
+        views::Background::CreateSolidBackground(
+            kShortcutBackgroundColor));
+  }
+
+  return wrapped_shortcut_label;
+}
+
+// Creates the candidate label, and returns it (never returns NULL).
+// The label text is not set in this function.
+views::Label* CreateCandidateLabel(
+    chromeos::InputMethodLookupTable::Orientation orientation) {
+  views::Label* candidate_label = NULL;
+
+  // Create the candidate label. The label will be added to |this| as a
+  // child view, hence it's deleted when |this| is deleted.
+  if (orientation == chromeos::InputMethodLookupTable::kVertical) {
+    candidate_label = new VerticalCandidateLabel;
+  } else {
+    candidate_label = new views::Label;
+  }
+
+  // Change the font size.
+  candidate_label->SetFont(
+      candidate_label->font().DeriveFont(kFontSizeDelta));
+  candidate_label->SetHorizontalAlignment(views::Label::ALIGN_LEFT);
+
+  return candidate_label;
+}
+
+// Computes shortcut column width.
+int ComputeShortcutColumnWidth(
+    const chromeos::InputMethodLookupTable& lookup_table) {
+  int shortcut_column_width = 0;
+  // Create the shortcut label. The label will be owned by
+  // |wrapped_shortcut_label|, hence it's deleted when
+  // |wrapped_shortcut_label| is deleted.
+  views::Label* shortcut_label = CreateShortcutLabel(lookup_table.orientation);
+  scoped_ptr<views::View> wrapped_shortcut_label(
+      CreateWrappedShortcutLabel(shortcut_label, lookup_table.orientation));
+
+  // Compute the max width in shortcut labels.
+  // We'll create temporary shortcut labels, and choose the largest width.
+  for (int i = 0; i < lookup_table.page_size; ++i) {
+    shortcut_label->SetText(
+        CreateShortcutText(i, lookup_table.orientation));
+    shortcut_column_width =
+        std::max(shortcut_column_width,
+                 wrapped_shortcut_label->GetPreferredSize().width());
+  }
+
+  return shortcut_column_width;
+}
+
+// Computes candidate column width.
+int ComputeCandidateColumnWidth(
+    const chromeos::InputMethodLookupTable& lookup_table) {
+  int candidate_column_width = 0;
+  scoped_ptr<views::Label> candidate_label(
+      CreateCandidateLabel(lookup_table.orientation));
+
+  // Compute the start index of |lookup_table_|.
+  const int current_page_index =
+      lookup_table.cursor_absolute_index / lookup_table.page_size;
+  const size_t start_from = current_page_index * lookup_table.page_size;
+
+  // Compute the max width in candidate labels.
+  // We'll create temporary candidate labels, and choose the largest width.
+  for (size_t i = 0; i < lookup_table.candidates.size(); ++i) {
+    const size_t index = start_from + i;
+
+    candidate_label->SetText(
+        UTF8ToWide(lookup_table.candidates[index]));
+    candidate_column_width =
+        std::max(candidate_column_width,
+                 candidate_label->GetPreferredSize().width());
+  }
+
+  return candidate_column_width;
+}
+
 }  // namespace
 
 namespace chromeos {
@@ -166,8 +337,7 @@ class CandidateWindowView : public views::View {
  private:
   // Initializes the candidate views if needed.
   void MaybeInitializeCandidateViews(
-      int num_views,
-      InputMethodLookupTable::Orientation orientation);
+      const InputMethodLookupTable& lookup_table);
 
   // Creates the footer area, where we show status information.
   // For instance, we show a cursor position like 2/19.
@@ -219,6 +389,10 @@ class CandidateWindowView : public views::View {
   views::Label* header_label_;
   // The footer label is shown in the footer area.
   views::Label* footer_label_;
+
+  // Current columns width in |candidate_area_|.
+  int previous_shortcut_column_width_;
+  int previous_candidate_column_width_;
 };
 
 // CandidateRow renderes a row of a candidate.
@@ -228,7 +402,10 @@ class CandidateView : public views::View {
                 int index_in_page,
                 InputMethodLookupTable::Orientation orientation);
   virtual ~CandidateView() {}
-  void Init();
+  // Initializes the candidate view with the given column widths.
+  // A width of 0 means that the column is resizable.
+  void Init(int shortcut_column_width,
+            int candidate_column_width);
 
   // Sets candidate text to the given text.
   void SetCandidateText(const std::wstring& text);
@@ -236,9 +413,6 @@ class CandidateView : public views::View {
   // Sets shortcut text to the given text.
   void SetShortcutText(const std::wstring& text);
 
-  // Sets shortcut text from the given integer.
-  void SetShortcutTextFromInt(int index);
-
   // Selects the candidate row. Changes the appearance to make it look
   // like a selected candidate.
   void Select();
@@ -283,29 +457,6 @@ class CandidateView : public views::View {
   views::Label* candidate_label_;
 };
 
-// VerticalCandidateLabel is used for rendering candidate text in
-// the vertical candidate window.
-class VerticalCandidateLabel : public views::Label {
-  virtual ~VerticalCandidateLabel() {}
-
-  // Returns the preferred size, but guarantees that the width has at
-  // least kMinCandidateLabelWidth pixels.
-  virtual gfx::Size GetPreferredSize() {
-    gfx::Size size = Label::GetPreferredSize();
-    // Hack. +2 is needed to prevent labels from getting elided like
-    // "abc..." in some cases. TODO(satorux): Figure out why it's
-    // necessary.
-    size.set_width(size.width() + 2);
-    if (size.width() < kMinCandidateLabelWidth) {
-      size.set_width(kMinCandidateLabelWidth);
-    }
-    if (size.width() > kMaxCandidateLabelWidth) {
-      size.set_width(kMaxCandidateLabelWidth);
-    }
-    return size;
-  }
-};
-
 // CandidateWindowController controls the CandidateWindow.
 class CandidateWindowController : public CandidateWindowView::Observer {
  public:
@@ -316,7 +467,7 @@ class CandidateWindowController : public CandidateWindowView::Observer {
   // Returns the work area of the monitor nearest the candidate window.
   gfx::Rect GetMonitorWorkAreaNearestWindow();
 
-  // Moves the candidate window per the the given cursor location, and the
+  // Moves the candidate window per the given cursor location, and the
   // horizontal offset.
   void MoveCandidateWindow(const gfx::Rect& cursor_location,
                            int horizontal_offset);
@@ -388,74 +539,38 @@ CandidateView::CandidateView(
       candidate_label_(NULL) {
 }
 
-void CandidateView::Init() {
+void CandidateView::Init(int shortcut_column_width,
+                         int candidate_column_width) {
   views::GridLayout* layout = new views::GridLayout(this);
   SetLayoutManager(layout);  // |this| owns |layout|.
 
-  // Create the shortcut label. The label will eventually be part of the
-  // tree of |this| via |wrapped_shortcut_label|, hence it's deleted when
-  // |this| is deleted.
-  shortcut_label_ = new views::Label();
-
-  // Wrap it with padding.
-  const gfx::Insets kVerticalShortcutLabelInsets(1, 6, 1, 6);
-  const gfx::Insets kHorizontalShortcutLabelInsets(1, 3, 1, 0);
-  const gfx::Insets insets =
-      (orientation_ == InputMethodLookupTable::kVertical ?
-       kVerticalShortcutLabelInsets :
-       kHorizontalShortcutLabelInsets);
+  // Create Labels.
+  shortcut_label_ = CreateShortcutLabel(orientation_);
   views::View* wrapped_shortcut_label =
-      WrapWithPadding(shortcut_label_, insets);
-  // We'll use a bigger font size, so Chinese characters are more readable
-  // in the candidate window.
-  const int kFontSizeDelta = 2;  // Two size bigger.
-  // Make the font bold, and change the size.
-  if (orientation_ == InputMethodLookupTable::kVertical) {
-    shortcut_label_->SetFont(
-        shortcut_label_->font().DeriveFont(kFontSizeDelta, gfx::Font::BOLD));
-  } else {
-    shortcut_label_->SetFont(
-        shortcut_label_->font().DeriveFont(kFontSizeDelta));
-  }
-  // TODO(satorux): Maybe we need to use language specific fonts for
-  // candidate_label, like Chinese font for Chinese input method?
+      CreateWrappedShortcutLabel(shortcut_label_, orientation_);
+  candidate_label_ = CreateCandidateLabel(orientation_);
 
-  // Add decoration based on the orientation.
-  if (orientation_ == InputMethodLookupTable::kVertical) {
-    // Set the background color.
-    wrapped_shortcut_label->set_background(
-        views::Background::CreateSolidBackground(
-            kShortcutBackgroundColor));
-  }
-  shortcut_label_->SetColor(kShortcutColor);
+  // Initialize the column set with two columns.
+  views::ColumnSet* column_set = layout->AddColumnSet(0);
 
-  // Create the candidate label. The label will be added to |this| as a
-  // child view, hence it's deleted when |this| is deleted.
-  if (orientation_ == InputMethodLookupTable::kVertical) {
-    candidate_label_ = new VerticalCandidateLabel;
-  } else {
-    candidate_label_ = new views::Label;
-  }
-  // Change the font size.
-  candidate_label_->SetFont(
-      candidate_label_->font().DeriveFont(kFontSizeDelta));
+  // If orientation is vertical, each column width is fixed.
+  // Otherwise the width is resizable.
+  const views::GridLayout::SizeType column_type =
+      orientation_ == InputMethodLookupTable::kVertical ?
+          views::GridLayout::FIXED : views::GridLayout::USE_PREF;
 
-  candidate_label_->SetHorizontalAlignment(views::Label::ALIGN_LEFT);
+  const int padding_column_width =
+      orientation_ == InputMethodLookupTable::kVertical ? 4 : 6;
 
-  // Initialize the column set with two columns.
-  views::ColumnSet* column_set = layout->AddColumnSet(0);
+  // Set shortcut column type and width.
   column_set->AddColumn(views::GridLayout::FILL, views::GridLayout::FILL,
-                        0, views::GridLayout::USE_PREF, 0, 0);
-  if (orientation_ == InputMethodLookupTable::kVertical) {
-    column_set->AddPaddingColumn(0, 4);
-  }
+                        0, column_type, shortcut_column_width, 0);
+  column_set->AddPaddingColumn(0, padding_column_width);
+
+  // Set candidate column type and width.
   column_set->AddColumn(views::GridLayout::FILL, views::GridLayout::FILL,
-                        0, views::GridLayout::USE_PREF, 0, 0);
-  if (orientation_ == InputMethodLookupTable::kVertical) {
-    column_set->AddPaddingColumn(0, 4);
-  } else {
-    column_set->AddPaddingColumn(0, 6);
-  }
+                        0, column_type, candidate_column_width, 0);
+  column_set->AddPaddingColumn(0, padding_column_width);
 
   // Add the shortcut label and the candidate label.
   layout->StartRow(0, 0);
@@ -472,21 +587,6 @@ void CandidateView::SetShortcutText(const std::wstring& text) {
   shortcut_label_->SetText(text);
 }
 
-void CandidateView::SetShortcutTextFromInt(int index) {
-  // Choose the character used for the shortcut label.
-  const wchar_t kShortcutCharacters[] = L"1234567890ABCDEF";
-  // The default character should not be used but just in case.
-  wchar_t shortcut_character = L'?';
-  if (index < static_cast<int>(arraysize(kShortcutCharacters) - 1)) {
-    shortcut_character = kShortcutCharacters[index];
-  }
-  if (orientation_ == InputMethodLookupTable::kVertical) {
-    shortcut_label_->SetText(base::StringPrintf(L"%lc", shortcut_character));
-  } else {
-    shortcut_label_->SetText(base::StringPrintf(L"%lc.", shortcut_character));
-  }
-}
-
 void CandidateView::Select() {
   set_background(
       views::Background::CreateSolidBackground(kSelectedRowBackgroundColor));
@@ -542,7 +642,9 @@ CandidateWindowView::CandidateWindowView(
       footer_area_(NULL),
       header_area_(NULL),
       header_label_(NULL),
-      footer_label_(NULL) {
+      footer_label_(NULL),
+      previous_shortcut_column_width_(0),
+      previous_candidate_column_width_(0) {
 }
 
 void CandidateWindowView::Init() {
@@ -616,8 +718,11 @@ void CandidateWindowView::UpdateAuxiliaryText(const std::string& utf8_text) {
 void CandidateWindowView::UpdateCandidates(
     const InputMethodLookupTable& lookup_table) {
   // Initialize candidate views if necessary.
-  MaybeInitializeCandidateViews(lookup_table.page_size,
-                                lookup_table.orientation);
+  MaybeInitializeCandidateViews(lookup_table);
+
+  // In MaybeInitializeCandidateViews(),
+  // |lookup_table| values and |lookup_table_| values are compared,
+  // so this substitution is needed after the function.
   lookup_table_ = lookup_table;
 
   // Compute the index of the current page.
@@ -645,7 +750,8 @@ void CandidateWindowView::UpdateCandidates(
       // (ex. show 6, 7, 8, ... in empty rows when the number of
       // candidates is 5). Second, we want to add a period after each
       // shortcut label when the candidate window is horizontal.
-      candidate_view->SetShortcutTextFromInt(i);
+      candidate_view->SetShortcutText(
+          CreateShortcutText(i, lookup_table_.orientation));
     }
     // Set the candidate text.
     if (candidate_index < lookup_table_.candidates.size()) {
@@ -666,15 +772,35 @@ void CandidateWindowView::UpdateCandidates(
 }
 
 void CandidateWindowView::MaybeInitializeCandidateViews(
-    int num_views,
-    InputMethodLookupTable::Orientation orientation) {
-  // If the requested number of views matches the number of current views,
-  // just reuse these.
-  if (num_views == static_cast<int>(candidate_views_.size()) &&
-      orientation == lookup_table_.orientation) {
+    const InputMethodLookupTable& lookup_table) {
+  const InputMethodLookupTable::Orientation orientation =
+      lookup_table.orientation;
+  const int page_size = lookup_table.page_size;
+
+  // Current column width.
+  int shortcut_column_width = 0;
+  int candidate_column_width = 0;
+
+  // If orientation is horizontal, don't need to compute width,
+  // because each label is left aligned.
+  if (orientation == InputMethodLookupTable::kVertical) {
+    shortcut_column_width = ComputeShortcutColumnWidth(lookup_table);
+    candidate_column_width = ComputeCandidateColumnWidth(lookup_table);
+  }
+
+  // If the requested number of views matches the number of current views, and
+  // previous and current column width are same, just reuse these.
+  if (static_cast<int>(candidate_views_.size()) == page_size &&
+      lookup_table_.orientation == orientation &&
+      previous_shortcut_column_width_ == shortcut_column_width &&
+      previous_candidate_column_width_ == candidate_column_width) {
     return;
   }
 
+  // Update the previous column widths.
+  previous_shortcut_column_width_ = shortcut_column_width;
+  previous_candidate_column_width_ = candidate_column_width;
+
   // Clear the existing candidate_views if any.
   for (size_t i = 0; i < candidate_views_.size(); ++i) {
     candidate_area_->RemoveChildView(candidate_views_[i]);
@@ -691,7 +817,7 @@ void CandidateWindowView::MaybeInitializeCandidateViews(
                           views::GridLayout::FILL,
                           0, views::GridLayout::USE_PREF, 0, 0);
   } else {
-    for (int i = 0; i < num_views; ++i) {
+    for (int i = 0; i < page_size; ++i) {
       column_set->AddColumn(views::GridLayout::FILL,
                             views::GridLayout::FILL,
                             0, views::GridLayout::USE_PREF, 0, 0);
@@ -712,16 +838,25 @@ void CandidateWindowView::MaybeInitializeCandidateViews(
   if (orientation == InputMethodLookupTable::kHorizontal) {
     layout->StartRow(0, 0);
   }
-  for (int i = 0; i < num_views; ++i) {
+
+  for (int i = 0; i < page_size; ++i) {
     CandidateView* candidate_row = new CandidateView(this, i, orientation);
-    candidate_row->Init();
+    candidate_row->Init(shortcut_column_width, candidate_column_width);
     candidate_views_.push_back(candidate_row);
     if (orientation == InputMethodLookupTable::kVertical) {
       layout->StartRow(0, 0);
     }
-    // |candidate_row| will be owned by candidate_area_|.
+    // |candidate_row| will be owned by |candidate_area_|.
     layout->AddView(candidate_row);
   }
+
+  // Compute views size in |layout|.
+  // If we don't call this function, GetHorizontalOffset() often
+  // returns invalid value (returns 0), then candidate window
+  // moves right from the correct position in MoveCandidateWindow().
+  // TODO(nhiroki): Figure out why it returns invalid value.
+  // It seems that the x-position of the candidate labels is not set.
+  layout->Layout(this);
 }
 
 views::View* CandidateWindowView::CreateHeaderArea() {