[Autofill] Add basic version of GridLayout

chrome/browser/ui/cocoa/autofill/simple_grid_layout.mm

+// Copyright (c) 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 "chrome/browser/ui/cocoa/autofill/simple_grid_layout.h"
+
+#include <algorithm>
+
+#include "base/logging.h"
+#include "base/stl_util.h"
+
+namespace {
+const int kAutoColumnIdStart = 1000000;  // Starting ID for autogeneration.
+}
+
+// Encapsulates state for a single NSView in the layout
+class ViewState {
+ public:
+  ViewState(NSView* view, ColumnSet* column_set, int row, int column);
+
+  // Gets the current width of the column associated with this view.
+  float GetColumnWidth();
+
+  // Get the preferred height for specified width.
+  float GetHeightForWidth(float with);
+
+  Column* GetColumn() const { return column_set_->GetColumn(column_); }
+
+  int row_index()  { return row_; }
+  NSView* view() { return view_; }
+  float preferred_height() { return pref_height_; }
+  void set_preferred_height(float height) { pref_height_ = height; }
+
+ private:
+  NSView* view_;
+  ColumnSet* column_set_;
+  int row_;
+  int column_;
+  float pref_height_;
+};
+
+class LayoutElement {
+ public:
+  LayoutElement(float resize_percent, int fixed_width);
+  virtual ~LayoutElement() {}
+
+  template <class T>
+      static void ResetSizes(ScopedVector<T>* elements) {
+    // Reset the layout width of each column.
+    for (typename std::vector<T*>::iterator i = elements->begin();
+         i != elements->end(); ++i) {
+      (*i)->ResetSize();
+    }
+  }
+
+  template <class T>
+      static void CalculateLocationsFromSize(ScopedVector<T>* elements) {
+    // Reset the layout width of each column.
+    int location = 0;
+    for (typename std::vector<T*>::iterator i = elements->begin();
+         i != elements->end(); ++i) {
+      (*i)->SetLocation(location);
+      location += (*i)->Size();
+    }
+  }
+
+  float Size() { return size_; }
+
+  void ResetSize() {
+      size_ = fixed_width_;
+  }
+
+  void SetSize(float size) {
+    size_ = size;
+  }
+
+  float Location() const {
+    return location_;
+  }
+
+  // Adjusts the size of this LayoutElement to be the max of the current size
+  // and the specified size.
+  virtual void AdjustSize(float size) {
+    size_ = std::max(size_, size);
+  }
+
+  void SetLocation(float location) {
+    location_ = location;
+  }
+
+  bool IsResizable() {
+    return resize_percent_ > 0.0f;
+  }
+
+  float ResizePercent() {
+    return resize_percent_;
+  }
+
+ private:
+  float resize_percent_;
+  int fixed_width_;
+  float size_;
+  float location_;
+};
+
+LayoutElement::LayoutElement(float resize_percent, int fixed_width)
+    : resize_percent_(resize_percent),
+      fixed_width_(fixed_width),
+      size_(0),
+      location_(0) {
+}
+
+class Column : public LayoutElement {
+ public:
+   Column(float resize_percent, int fixed_width, bool is_padding);
+
+   bool is_padding() { return is_padding_; }
+
+  private:
+    const bool is_padding_;
+};
+
+Column::Column(float resize_percent, int fixed_width, bool is_padding)
+    : LayoutElement(resize_percent, fixed_width),
+      is_padding_(is_padding) {
+}
+
+class Row : public LayoutElement {
+ public:
+  Row(float resize_percent, int fixed_height, ColumnSet* column_set);
+
+  ColumnSet* column_set() { return column_set_; }
+
+ private:
+  ColumnSet* column_set_;
+};
+
+Row::Row(float resize_percent, int fixed_height, ColumnSet* column_set)
+    : LayoutElement(resize_percent, fixed_height),
+      column_set_(column_set) {
+}
+
+ViewState::ViewState(NSView* view, ColumnSet* column_set, int row, int column)
+    : view_(view),
+      column_set_(column_set),
+      row_(row),
+      column_(column) {}
+
+float ViewState::GetColumnWidth() {
+  return column_set_->GetColumnWidth(column_);
+}
+
+float ViewState::GetHeightForWidth(float width) {
+  // NSView doesn't have any way to make height fit size, get frame height.
+  return NSHeight([view_ frame]);
+}
+
+ColumnSet::ColumnSet(int id) : id_(id) {
+}
+
+ColumnSet::~ColumnSet() {
+}
+
+void ColumnSet::AddPaddingColumn(int fixed_width) {
+  columns_.push_back(new Column(0.0f, fixed_width, true));
+}
+
+void ColumnSet::AddColumn(float resize_percent) {
+  columns_.push_back(new Column(resize_percent, 0, false));
+}
+
+void ColumnSet::CalculateSize(float width) {
+  // Reset column widths
+  LayoutElement::ResetSizes(&columns_);
+  width = CalculateRemainingWidth(width);
+  DistributeRemainingWidth(width);
+}
+
+void ColumnSet::ResetColumnXCoordinates() {
+  LayoutElement::CalculateLocationsFromSize(&columns_);
+}
+
+float ColumnSet::CalculateRemainingWidth(float width) {
+  for (size_t i = 0; i < columns_.size(); ++i)
+    width -= columns_[i]->Size();
+
+  return width;
+}
+
+void ColumnSet::DistributeRemainingWidth(float width) {
+  float total_resize = 0.0f;
+  int resizable_columns = 0.0;
+
+  for (size_t i = 0; i < columns_.size(); ++i) {
+    if (columns_[i]->IsResizable()) {
+      total_resize += columns_[i]->ResizePercent();
+      resizable_columns++;
+    }
+  }
+
+  float remaining_width = width;
+  for (size_t i = 0; i < columns_.size(); ++i) {
+    if (columns_[i]->IsResizable()) {
+      float delta = (resizable_columns == 0) ? remaining_width :
+          (width * columns_[i]->ResizePercent() / total_resize);
+      remaining_width -= delta;
+      columns_[i]->SetSize(columns_[i]->Size() + delta);
+      resizable_columns--;
+    }
+  }
+}
+
+float ColumnSet::GetColumnWidth(int column_index) {
+  if (column_index < 0 || column_index >= num_columns())
+    return 0.0;
+  return columns_[column_index]->Size();
+}
+
+float ColumnSet::ColumnLocation(int column_index) {
+  if (column_index < 0 || column_index >= num_columns())
+    return 0.0;
+  return columns_[column_index]->Location();
+}
+
+SimpleGridLayout::SimpleGridLayout(NSView* host)
+    : next_column_(0),
+      current_auto_id_(kAutoColumnIdStart),
+      host_(host) {
+  [host_ frame];
+}
+
+SimpleGridLayout::~SimpleGridLayout() {
+}
+
+ColumnSet* SimpleGridLayout::AddColumnSet(int id) {
+  DCHECK(GetColumnSet(id) == NULL);
+  ColumnSet* column_set = new ColumnSet(id);
+  column_sets_.push_back(column_set);
+  return column_set;
+}
+
+ColumnSet* SimpleGridLayout::GetColumnSet(int id) {
+  for (ScopedVector<ColumnSet>::const_iterator i = column_sets_.begin();
+       i != column_sets_.end(); ++i) {
+    if ((*i)->id() == id) {
+      return *i;
+    }
+  }
+  return NULL;
+}
+
+void SimpleGridLayout::AddPaddingRow(int fixed_height) {
+  AddRow(new Row(0.0f, fixed_height, NULL));
+}
+
+void SimpleGridLayout::StartRow(float vertical_resize, int column_set_id) {
+  ColumnSet* column_set = GetColumnSet(column_set_id);
+  DCHECK(column_set);
+  AddRow(new Row(vertical_resize, 0, column_set));
+}
+
+ColumnSet* SimpleGridLayout::AddRow() {
+  AddRow(new Row(0, 0, AddColumnSet(current_auto_id_++)));
+  return column_sets_.back();
+}
+
+void SimpleGridLayout::SkipColumns(int col_count) {
+  DCHECK(col_count > 0);
+  next_column_ += col_count;
+  ColumnSet* current_row_col_set_ = GetLastValidColumnSet();
+  DCHECK(current_row_col_set_ &&
+         next_column_ <= current_row_col_set_->num_columns());
+  SkipPaddingColumns();
+}
+
+void SimpleGridLayout::AddView(NSView* view) {
+  [host_ addSubview:view];
+  DCHECK(next_column_ < GetLastValidColumnSet()->num_columns());
+  view_states_.push_back(
+      new ViewState(view,
+                    GetLastValidColumnSet(),
+                    rows_.size() - 1,
+                    next_column_++));
+  SkipPaddingColumns();
+}
+
+// Sizes elements to fit into the superViews bounds, according to constraints.
+void SimpleGridLayout::Layout(NSView* superView) {
+  SizeRowsAndColumns(NSWidth([superView bounds]));
+  for (std::vector<ViewState*>::iterator i = view_states_.begin();
+       i != view_states_.end(); ++i) {
+    ViewState* view_state = *i;
+    NSView* view = view_state->view();
+    NSRect frame = NSMakeRect(view_state->GetColumn()->Location(),
+                              rows_[view_state->row_index()]->Location(),
+                              view_state->GetColumn()->Size(),
+                              rows_[view_state->row_index()]->Size());
+    [view setFrame:frame];
+  }
+}
+
+void SimpleGridLayout::SizeRowsAndColumns(float width) {
+  // Size all columns first.
+  for (ScopedVector<ColumnSet>::iterator i = column_sets_.begin();
+       i != column_sets_.end(); ++i) {
+    (*i)->CalculateSize(width);
+    (*i)->ResetColumnXCoordinates();
+  }
+
+  // Reset the height of each row.
+  LayoutElement::ResetSizes(&rows_);
+
+  // For each ViewState, obtain the preferred height
+  for (std::vector<ViewState*>::iterator i= view_states_.begin();
+       i != view_states_.end() ; ++i) {
+    ViewState* view_state = *i;
+
+    // The view is resizable. As the pref height may vary with the width,
+    // ask for the pref again.
+    int actual_width = view_state->GetColumnWidth();
+
+    // The width this view will get differs from its preferred. Some Views
+    // pref height varies with its width; ask for the preferred again.
+    view_state->set_preferred_height(
+        view_state->GetHeightForWidth(actual_width));
+  }
+
+
+  // Make sure each row can accommodate all contained ViewStates.
+  std::vector<ViewState*>::iterator view_states_iterator = view_states_.begin();
+  for (; view_states_iterator != view_states_.end(); ++view_states_iterator) {
+    ViewState* view_state = *view_states_iterator;
+    Row* row = rows_[view_state->row_index()];
+    row->AdjustSize(view_state->preferred_height());
+  }
+
+  // Update the location of each of the rows.
+  LayoutElement::CalculateLocationsFromSize(&rows_);
+}
+
+void SimpleGridLayout::SkipPaddingColumns() {
+  ColumnSet* current_row_col_set_ = GetLastValidColumnSet();
+  while (next_column_ < current_row_col_set_->num_columns() &&
+         current_row_col_set_->GetColumn(next_column_)->is_padding()) {
+    next_column_++;
+  }
+}
+
+ColumnSet* SimpleGridLayout::GetLastValidColumnSet() {
+  for (int i = num_rows() - 1; i >= 0; --i) {
+    if (rows_[i]->column_set())
+      return rows_[i]->column_set();
+  }
+  return NULL;
+}
+
+float SimpleGridLayout::GetRowHeight(int row_index) {
+  if (row_index < 0 || row_index >= num_rows())
+    return 0.0;
+  return rows_[row_index]->Size();
+}
+
+float SimpleGridLayout::GetRowLocation(int row_index) const {
+  if (row_index < 0 || row_index >= num_rows())
+    return 0.0;
+  return rows_[row_index]->Location();
+}
+
+float SimpleGridLayout::GetPreferredHeightForWidth(float width) {
+  if (rows_.empty())
+    return 0.0f;
+
+  SizeRowsAndColumns(width);
+  return rows_.back()->Location() + rows_.back()->Size();
+}
+
+void SimpleGridLayout::AddRow(Row* row) {
+  next_column_ = 0;
+  rows_.push_back(row);
+}
+