ui/views/controls/textfield/textfield_model.h

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef UI_VIEWS_CONTROLS_TEXTFIELD_TEXTFIELD_MODEL_H_
   6 #define UI_VIEWS_CONTROLS_TEXTFIELD_TEXTFIELD_MODEL_H_
   7
   8 #include <list>
   9 #include <vector>
  10
  11 #include "base/gtest_prod_util.h"
  12 #include "base/memory/scoped_ptr.h"
  13 #include "base/strings/string16.h"
  14 #include "ui/base/ime/composition_text.h"
  15 #include "ui/gfx/render_text.h"
  16 #include "ui/gfx/text_constants.h"
  17 #include "ui/views/views_export.h"
  18
  19 namespace views {
  20
  21 namespace internal {
  22 // Internal Edit class that keeps track of edits for undo/redo.
  23 class Edit;
  24
  25 // The types of merge behavior implemented by Edit operations.
  26 enum MergeType {
  27   // The edit should not usually be merged with next edit.
  28   DO_NOT_MERGE,
  29   // The edit should be merged with next edit when possible.
  30   MERGEABLE,
  31   // The edit should be merged with the prior edit, even if marked DO_NOT_MERGE.
  32   FORCE_MERGE,
  33 };
  34
  35 }  // namespace internal
  36
  37 // A model that represents text content for a views::Textfield.
  38 // It supports editing, selection and cursor manipulation.
  39 class VIEWS_EXPORT TextfieldModel {
  40  public:
  41   // Delegate interface implemented by the textfield view class to provide
  42   // additional functionalities required by the model.
  43   class VIEWS_EXPORT Delegate {
  44    public:
  45     // Called when the current composition text is confirmed or cleared.
  46     virtual void OnCompositionTextConfirmedOrCleared() = 0;
  47
  48    protected:
  49     virtual ~Delegate();
  50   };
  51
  52   explicit TextfieldModel(Delegate* delegate);
  53   virtual ~TextfieldModel();
  54
  55   // Edit related methods.
  56
  57   const base::string16& text() const { return render_text_->text(); }
  58   // Sets the text. Returns true if the text has been modified.  The current
  59   // composition text will be confirmed first.  Setting the same text will not
  60   // add edit history because it's not user visible change nor user-initiated
  61   // change. This allow a client code to set the same text multiple times
  62   // without worrying about messing edit history.
  63   bool SetText(const base::string16& new_text);
  64
  65   gfx::RenderText* render_text() { return render_text_.get(); }
  66
  67   // Inserts given |new_text| at the current cursor position.
  68   // The current composition text will be cleared.
  69   void InsertText(const base::string16& new_text) {
  70     InsertTextInternal(new_text, false);
  71   }
  72
  73   // Inserts a character at the current cursor position.
  74   void InsertChar(base::char16 c) {
  75     InsertTextInternal(base::string16(&c, 1), true);
  76   }
  77
  78   // Replaces characters at the current position with characters in given text.
  79   // The current composition text will be cleared.
  80   void ReplaceText(const base::string16& new_text) {
  81     ReplaceTextInternal(new_text, false);
  82   }
  83
  84   // Replaces the char at the current position with given character.
  85   void ReplaceChar(base::char16 c) {
  86     ReplaceTextInternal(base::string16(&c, 1), true);
  87   }
  88
  89   // Appends the text.
  90   // The current composition text will be confirmed.
  91   void Append(const base::string16& new_text);
  92
  93   // Deletes the first character after the current cursor position (as if, the
  94   // the user has pressed delete key in the textfield). Returns true if
  95   // the deletion is successful.
  96   // If there is composition text, it'll be deleted instead.
  97   bool Delete();
  98
  99   // Deletes the first character before the current cursor position (as if, the
 100   // the user has pressed backspace key in the textfield). Returns true if
 101   // the removal is successful.
 102   // If there is composition text, it'll be deleted instead.
 103   bool Backspace();
 104
 105   // Cursor related methods.
 106
 107   // Returns the current cursor position.
 108   size_t GetCursorPosition() const;
 109
 110   // Moves the cursor, see RenderText for additional details.
 111   // The current composition text will be confirmed.
 112   void MoveCursor(gfx::BreakType break_type,
 113                   gfx::VisualCursorDirection direction,
 114                   bool select);
 115
 116   // Updates the cursor to the specified selection model. Any composition text
 117   // will be confirmed, which may alter the specified selection range start.
 118   bool MoveCursorTo(const gfx::SelectionModel& cursor);
 119
 120   // Helper function to call MoveCursorTo on the TextfieldModel.
 121   bool MoveCursorTo(const gfx::Point& point, bool select);
 122
 123   // Selection related methods.
 124
 125   // Returns the selected text.
 126   base::string16 GetSelectedText() const;
 127
 128   // The current composition text will be confirmed. The selection starts with
 129   // the range's start position, and ends with the range's end position,
 130   // therefore the cursor position becomes the end position.
 131   void SelectRange(const gfx::Range& range);
 132
 133   // The current composition text will be confirmed.
 134   // render_text_'s selection model is set to |sel|.
 135   void SelectSelectionModel(const gfx::SelectionModel& sel);
 136
 137   // Select the entire text range. If |reversed| is true, the range will end at
 138   // the logical beginning of the text; this generally shows the leading portion
 139   // of text that overflows its display area.
 140   // The current composition text will be confirmed.
 141   void SelectAll(bool reversed);
 142
 143   // Selects the word at which the cursor is currently positioned. If there is a
 144   // non-empty selection, the selection bounds are extended to their nearest
 145   // word boundaries.
 146   // The current composition text will be confirmed.
 147   void SelectWord();
 148
 149   // Clears selection.
 150   // The current composition text will be confirmed.
 151   void ClearSelection();
 152
 153   // Returns true if there is an undoable edit.
 154   bool CanUndo();
 155
 156   // Returns true if there is an redoable edit.
 157   bool CanRedo();
 158
 159   // Undo edit. Returns true if undo changed the text.
 160   bool Undo();
 161
 162   // Redo edit. Returns true if redo changed the text.
 163   bool Redo();
 164
 165   // Cuts the currently selected text and puts it to clipboard. Returns true
 166   // if text has changed after cutting.
 167   bool Cut();
 168
 169   // Copies the currently selected text and puts it to clipboard. Returns true
 170   // if something was copied to the clipboard.
 171   bool Copy();
 172
 173   // Pastes text from the clipboard at current cursor position. Returns true
 174   // if any text is pasted.
 175   bool Paste();
 176
 177   // Tells if any text is selected, even if the selection is in composition
 178   // text.
 179   bool HasSelection() const;
 180
 181   // Deletes the selected text. This method shouldn't be called with
 182   // composition text.
 183   void DeleteSelection();
 184
 185   // Deletes the selected text (if any) and insert text at given position.
 186   void DeleteSelectionAndInsertTextAt(const base::string16& new_text,
 187                                       size_t position);
 188
 189   // Retrieves the text content in a given range.
 190   base::string16 GetTextFromRange(const gfx::Range& range) const;
 191
 192   // Retrieves the range containing all text in the model.
 193   void GetTextRange(gfx::Range* range) const;
 194
 195   // Sets composition text and attributes. If there is composition text already,
 196   // it'll be replaced by the new one. Otherwise, current selection will be
 197   // replaced. If there is no selection, the composition text will be inserted
 198   // at the insertion point.
 199   // Any changes to the model except text insertion will confirm the current
 200   // composition text.
 201   void SetCompositionText(const ui::CompositionText& composition);
 202
 203   // Converts current composition text into final content.
 204   void ConfirmCompositionText();
 205
 206   // Removes current composition text.
 207   void CancelCompositionText();
 208
 209   // Retrieves the range of current composition text.
 210   void GetCompositionTextRange(gfx::Range* range) const;
 211
 212   // Returns true if there is composition text.
 213   bool HasCompositionText() const;
 214
 215   // Clears all edit history.
 216   void ClearEditHistory();
 217
 218  private:
 219   friend class internal::Edit;
 220
 221   FRIEND_TEST_ALL_PREFIXES(TextfieldModelTest, UndoRedo_BasicTest);
 222   FRIEND_TEST_ALL_PREFIXES(TextfieldModelTest, UndoRedo_CutCopyPasteTest);
 223   FRIEND_TEST_ALL_PREFIXES(TextfieldModelTest, UndoRedo_ReplaceTest);
 224
 225   // Insert the given |new_text|. |mergeable| indicates if this insert operation
 226   // can be merged with previous edits in the history.
 227   void InsertTextInternal(const base::string16& new_text, bool mergeable);
 228
 229   // Replace the current text with the given |new_text|. |mergeable| indicates
 230   // if this replace operation can be merged with previous edits in the history.
 231   void ReplaceTextInternal(const base::string16& new_text, bool mergeable);
 232
 233   // Clears redo history.
 234   void ClearRedoHistory();
 235
 236   // Executes and records edit operations.
 237   void ExecuteAndRecordDelete(gfx::Range range, bool mergeable);
 238   void ExecuteAndRecordReplaceSelection(internal::MergeType merge_type,
 239                                         const base::string16& new_text);
 240   void ExecuteAndRecordReplace(internal::MergeType merge_type,
 241                                size_t old_cursor_pos,
 242                                size_t new_cursor_pos,
 243                                const base::string16& new_text,
 244                                size_t new_text_start);
 245   void ExecuteAndRecordInsert(const base::string16& new_text, bool mergeable);
 246
 247   // Adds or merge |edit| into edit history. Return true if the edit
 248   // has been merged and must be deleted after redo.
 249   bool AddOrMergeEditHistory(internal::Edit* edit);
 250
 251   // Modify the text buffer in following way:
 252   // 1) Delete the string from |delete_from| to |delte_to|.
 253   // 2) Insert the |new_text| at the index |new_text_insert_at|.
 254   //    Note that the index is after deletion.
 255   // 3) Move the cursor to |new_cursor_pos|.
 256   void ModifyText(size_t delete_from,
 257                   size_t delete_to,
 258                   const base::string16& new_text,
 259                   size_t new_text_insert_at,
 260                   size_t new_cursor_pos);
 261
 262   void ClearComposition();
 263
 264   // The TextfieldModel::Delegate instance should be provided by the owner.
 265   Delegate* delegate_;
 266
 267   // The stylized text, cursor, selection, and the visual layout model.
 268   scoped_ptr<gfx::RenderText> render_text_;
 269
 270   // The composition range.
 271   gfx::Range composition_range_;
 272
 273   typedef std::list<internal::Edit*> EditHistory;
 274   EditHistory edit_history_;
 275
 276   // An iterator that points to the current edit that can be undone.
 277   // This iterator moves from the |end()|, meaining no edit to undo,
 278   // to the last element (one before |end()|), meaning no edit to redo.
 279   //
 280   // There is no edit to undo (== end()) when:
 281   //   1) in initial state. (nothing to undo)
 282   //   2) very 1st edit is undone.
 283   //   3) all edit history is removed.
 284   // There is no edit to redo (== last element or no element) when:
 285   //   1) in initial state. (nothing to redo)
 286   //   2) new edit is added. (redo history is cleared)
 287   //   3) redone all undone edits.
 288   EditHistory::iterator current_edit_;
 289
 290   DISALLOW_COPY_AND_ASSIGN(TextfieldModel);
 291 };
 292
 293 }  // namespace views
 294
 295 #endif  // UI_VIEWS_CONTROLS_TEXTFIELD_TEXTFIELD_MODEL_H_