[Autofill] Add basic version of GridLayout

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

+// 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.
+
+#ifndef CHROME_BROWSER_UI_COCOA_AUTOFILL_SIMPLE_GRID_LAYOUT_H_
+#define CHROME_BROWSER_UI_COCOA_AUTOFILL_SIMPLE_GRID_LAYOUT_H_
+
+#import <Cocoa/Cocoa.h>
+
+#include "base/memory/scoped_ptr.h"
+#include "base/memory/scoped_vector.h"
+
+class Column;
+class ColumnSet;
+class Row;
+class ViewState;
+
+// SimpleGridLayout is a layout manager that positions child views in a grid.
+// Each row has exactly one ColumnSet, ColumnSets can be shared between rows.
+// See ui/views/layout/grid_layout.h for more details - this is a very
+// simplified version of the views class.
+// This is based on GridLayout in ui/views/layout/grid_layout.h.
+// TODO(groby): Unify both classes, create cross-platform abstraction.
+// http://crbug.com/240461
+class SimpleGridLayout {
+ public:
+  SimpleGridLayout(NSView* host);
+  ~SimpleGridLayout();
+
+  // Creates a new column set with the specified id and returns it.
+  // The id is later used when starting a new row.
+  // Layout takes ownership of the ColumnSet and will delete it when
+  // it is deleted.
+  ColumnSet* AddColumnSet(int id);
+
+  // Returns the column set for the specified id, or NULL if one doesn't exist.
+  ColumnSet* GetColumnSet(int id);
+
+  // Adds a padding row. Padding rows typically don't have any views, but are
+  // used to provide vertical white space between views.
+  // |size| specifies the height of the row.
+  void AddPaddingRow(int size);
+
+  // Starts a new row with the specified column set.
+  void StartRow(float vertical_resize, int column_set_id);
+
+  // This is a convenience function that starts a new row,
+  // and returns a new ColumnSet associated with it. All rows created by this
+  // will have a height of 0 and resize_percent set to 1.0.
+  ColumnSet* AddRow();
+
+  // Advances past columns. Use this when the current column should not
+  // contain any views.
+  void SkipColumns(int col_count);
+
+  // TODO(groby): This currently *must* be called after a StartRow for the row
+  // the view is in. At some point, I'd like an AddView that just populates
+  // the next available slot, if possible.
+  void AddView(NSView* view);
+
+  // Layout all contained views according to constraints.
+  void Layout(NSView* superView);
+
+  void SizeRowsAndColumns(float width);
+
+  // Advances next_column_ past any padding columns.
+  void SkipPaddingColumns();
+
+  // Returns the column set of the last non-padding row.
+  ColumnSet* GetLastValidColumnSet();
+
+  // Get the height of a given row.
+  float GetRowHeight(int row);
+
+  // Y-position for a given row.
+  float GetRowLocation(int row_index) const;
+
+  // Get the preferred height for the given width.
+  float GetPreferredHeightForWidth(float with);
+
+  int num_rows() const { return static_cast<int>(rows_.size()); }
+
+  // These functions are mostly for testing & deviate from Views Layout class.
+  int next_column() { return next_column_; }
+  void AdvanceColumn() { next_column_++; }
+
+ private:
+  // Adds a new row, updating associated counters and positions.
+  void AddRow(Row* row);
+
+  // Next column in the current ColumnSet.
+  int next_column_;
+
+  int current_auto_id_;  // Starting value for autogenerated columnset ids.
+  ScopedVector<ViewState> view_states_;
+  ScopedVector<ColumnSet> column_sets_;
+  ScopedVector<Row> rows_;
+
+  NSView* host_;
+};
+
+// ColumnSet is used to define a set of columns.
+// You don't create a ColumnSet directly, instead use the AddRow method
+// of SimpleGridLayout.
+class ColumnSet {
+ public:
+  explicit ColumnSet(int id);
+  ~ColumnSet();
+
+  void AddPaddingColumn(int fixed_width);
+  void AddColumn(float resize_percent);
+
+  void CalculateSize(float width);
+  void ResetColumnXCoordinates();
+
+  // ID of this ColumnSet.
+  int id() const { return id_; }
+
+  int num_columns() const { return static_cast<int>(columns_.size()); }
+
+  // Returns the width of the specified columns.
+  float GetColumnWidth(int column);
+
+  Column* GetColumn(int column_index) {
+    DCHECK(column_index >=0 && column_index < num_columns());
+    return columns_[column_index];
+  }
+
+  // These functions are mostly for testing & deviate from Views Layout class.
+  float ColumnLocation(int column_index);
+
+ private:
+  float CalculateRemainingWidth(float width);
+  void DistributeRemainingWidth(float width);
+
+  ScopedVector<Column> columns_;
+  int id_;
+};
+
+#endif  // CHROME_BROWSER_UI_COCOA_AUTOFILL_SIMPLE_GRID_LAYOUT_H_