// 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.

#ifndef UI_VIEWS_CONTROLS_TEXTFIELD_TEXTFIELD_H_
#define UI_VIEWS_CONTROLS_TEXTFIELD_TEXTFIELD_H_

#include <string>

#include "base/basictypes.h"
#include "base/compiler_specific.h"
#include "base/memory/scoped_ptr.h"
#include "base/memory/weak_ptr.h"
#include "base/strings/string16.h"
#include "base/timer/timer.h"
#include "third_party/skia/include/core/SkColor.h"
#include "ui/base/ime/text_input_client.h"
#include "ui/base/ime/text_input_type.h"
#include "ui/base/models/simple_menu_model.h"
#include "ui/base/touch/touch_editing_controller.h"
#include "ui/events/keycodes/keyboard_codes.h"
#include "ui/gfx/font_list.h"
#include "ui/gfx/range/range.h"
#include "ui/gfx/selection_model.h"
#include "ui/gfx/text_constants.h"
#include "ui/views/context_menu_controller.h"
#include "ui/views/controls/textfield/textfield_model.h"
#include "ui/views/drag_controller.h"
#include "ui/views/view.h"

namespace views {

class MenuRunner;
class Painter;
class TextfieldController;

// A views/skia textfield implementation. No platform-specific code is used.
class VIEWS_EXPORT Textfield : public View,
                               public TextfieldModel::Delegate,
                               public ContextMenuController,
                               public DragController,
                               public ui::TouchEditable,
                               public ui::TextInputClient {
 public:
  // The textfield's class name.
  static const char kViewClassName[];

  // The preferred size of the padding to be used around textfield text.
  static const int kTextPadding;

  // Returns the text cursor blink time in milliseconds, or 0 for no blinking.
  static size_t GetCaretBlinkMs();

  Textfield();
  ~Textfield() override;

  // Set the controller for this textfield.
  void set_controller(TextfieldController* controller) {
    controller_ = controller;
  }

  // Gets/Sets whether or not the Textfield is read-only.
  bool read_only() const { return read_only_; }
  void SetReadOnly(bool read_only);

  // Sets the input type; displays only asterisks for TEXT_INPUT_TYPE_PASSWORD.
  void SetTextInputType(ui::TextInputType type);

  // Gets the text currently displayed in the Textfield.
  const base::string16& text() const { return model_->text(); }

  // Sets the text currently displayed in the Textfield.  This doesn't
  // change the cursor position if the current cursor is within the
  // new text's range, or moves the cursor to the end if the cursor is
  // out of the new text's range.
  void SetText(const base::string16& new_text);

  // Appends the given string to the previously-existing text in the field.
  void AppendText(const base::string16& new_text);

  // Inserts |new_text| at the cursor position, replacing any selected text.
  void InsertOrReplaceText(const base::string16& new_text);

  // Returns the text direction.
  base::i18n::TextDirection GetTextDirection() const;

  // Returns the text that is currently selected.
  base::string16 GetSelectedText() const;

  // Select the entire text range. If |reversed| is true, the range will end at
  // the logical beginning of the text; this generally shows the leading portion
  // of text that overflows its display area.
  void SelectAll(bool reversed);

  // A convenience method to select the word closest to |point|.
  void SelectWordAt(const gfx::Point& point);

  // Clears the selection within the edit field and sets the caret to the end.
  void ClearSelection();

  // Checks if there is any selected text.
  bool HasSelection() const;

  // Gets/sets the text color to be used when painting the Textfield.
  // Call UseDefaultTextColor() to restore the default system color.
  SkColor GetTextColor() const;
  void SetTextColor(SkColor color);
  void UseDefaultTextColor();

  // Gets/sets the background color to be used when painting the Textfield.
  // Call UseDefaultBackgroundColor() to restore the default system color.
  SkColor GetBackgroundColor() const;
  void SetBackgroundColor(SkColor color);
  void UseDefaultBackgroundColor();

  // Gets/sets the selection text color to be used when painting the Textfield.
  // Call UseDefaultSelectionTextColor() to restore the default system color.
  SkColor GetSelectionTextColor() const;
  void SetSelectionTextColor(SkColor color);
  void UseDefaultSelectionTextColor();

  // Gets/sets the selection background color to be used when painting the
  // Textfield. Call UseDefaultSelectionBackgroundColor() to restore the default
  // system color.
  SkColor GetSelectionBackgroundColor() const;
  void SetSelectionBackgroundColor(SkColor color);
  void UseDefaultSelectionBackgroundColor();

  // Set drop shadows underneath the text.
  void SetShadows(const gfx::ShadowValues& shadows);

  // Gets/Sets whether or not the cursor is enabled.
  bool GetCursorEnabled() const;
  void SetCursorEnabled(bool enabled);

  // Gets/Sets the fonts used when rendering the text within the Textfield.
  const gfx::FontList& GetFontList() const;
  void SetFontList(const gfx::FontList& font_list);

  // Sets the default width of the text control. See default_width_in_chars_.
  void set_default_width_in_chars(int default_width) {
    default_width_in_chars_ = default_width;
  }

  // Sets the text to display when empty.
  void set_placeholder_text(const base::string16& text) {
    placeholder_text_ = text;
  }
  virtual base::string16 GetPlaceholderText() const;

  SkColor placeholder_text_color() const { return placeholder_text_color_; }
  void set_placeholder_text_color(SkColor color) {
    placeholder_text_color_ = color;
  }

  // Get or set the horizontal alignment used for the button from the underlying
  // RenderText object.
  gfx::HorizontalAlignment GetHorizontalAlignment() const;
  void SetHorizontalAlignment(gfx::HorizontalAlignment alignment);

  // Displays a virtual keyboard or alternate input view if enabled.
  void ShowImeIfNeeded();

  // Returns whether or not an IME is composing text.
  bool IsIMEComposing() const;

  // Gets the selected logical text range.
  const gfx::Range& GetSelectedRange() const;

  // Selects the specified logical text range.
  void SelectRange(const gfx::Range& range);

  // Gets the text selection model.
  const gfx::SelectionModel& GetSelectionModel() const;

  // Sets the specified text selection model.
  void SelectSelectionModel(const gfx::SelectionModel& sel);

  // Returns the current cursor position.
  size_t GetCursorPosition() const;

  // Set the text color over the entire text or a logical character range.
  // Empty and invalid ranges are ignored.
  void SetColor(SkColor value);
  void ApplyColor(SkColor value, const gfx::Range& range);

  // Set various text styles over the entire text or a logical character range.
  // The respective |style| is applied if |value| is true, or removed if false.
  // Empty and invalid ranges are ignored.
  void SetStyle(gfx::TextStyle style, bool value);
  void ApplyStyle(gfx::TextStyle style, bool value, const gfx::Range& range);

  // Clears Edit history.
  void ClearEditHistory();

  // Set the accessible name of the text field.
  void SetAccessibleName(const base::string16& name);

  // Performs the action associated with the specified command id.
  void ExecuteCommand(int command_id);

  void SetFocusPainter(scoped_ptr<Painter> focus_painter);

  // Returns whether there is a drag operation originating from the textfield.
  bool HasTextBeingDragged();

  // View overrides:
  gfx::Insets GetInsets() const override;
  int GetBaseline() const override;
  gfx::Size GetPreferredSize() const override;
  const char* GetClassName() const override;
  gfx::NativeCursor GetCursor(const ui::MouseEvent& event) override;
  bool OnMousePressed(const ui::MouseEvent& event) override;
  bool OnMouseDragged(const ui::MouseEvent& event) override;
  void OnMouseReleased(const ui::MouseEvent& event) override;
  bool OnKeyPressed(const ui::KeyEvent& event) override;
  ui::TextInputClient* GetTextInputClient() override;
  void OnGestureEvent(ui::GestureEvent* event) override;
  void AboutToRequestFocusFromTabTraversal(bool reverse) override;
  bool SkipDefaultKeyEventProcessing(const ui::KeyEvent& event) override;
  bool GetDropFormats(
      int* formats,
      std::set<ui::OSExchangeData::CustomFormat>* custom_formats) override;
  bool CanDrop(const ui::OSExchangeData& data) override;
  int OnDragUpdated(const ui::DropTargetEvent& event) override;
  void OnDragExited() override;
  int OnPerformDrop(const ui::DropTargetEvent& event) override;
  void OnDragDone() override;
  void GetAccessibleState(ui::AXViewState* state) override;
  void OnBoundsChanged(const gfx::Rect& previous_bounds) override;
  bool GetNeedsNotificationWhenVisibleBoundsChange() const override;
  void OnVisibleBoundsChanged() override;
  void OnEnabledChanged() override;
  void OnPaint(gfx::Canvas* canvas) override;
  void OnFocus() override;
  void OnBlur() override;
  gfx::Point GetKeyboardContextMenuLocation() override;
  void OnNativeThemeChanged(const ui::NativeTheme* theme) override;

  // TextfieldModel::Delegate overrides:
  void OnCompositionTextConfirmedOrCleared() override;

  // ContextMenuController overrides:
  void ShowContextMenuForView(View* source,
                              const gfx::Point& point,
                              ui::MenuSourceType source_type) override;

  // DragController overrides:
  void WriteDragDataForView(View* sender,
                            const gfx::Point& press_pt,
                            ui::OSExchangeData* data) override;
  int GetDragOperationsForView(View* sender, const gfx::Point& p) override;
  bool CanStartDragForView(View* sender,
                           const gfx::Point& press_pt,
                           const gfx::Point& p) override;

  // ui::TouchEditable overrides:
  void SelectRect(const gfx::Point& start, const gfx::Point& end) override;
  void MoveCaretTo(const gfx::Point& point) override;
  void GetSelectionEndPoints(ui::SelectionBound* anchor,
                             ui::SelectionBound* focus) override;
  gfx::Rect GetBounds() override;
  gfx::NativeView GetNativeView() const override;
  void ConvertPointToScreen(gfx::Point* point) override;
  void ConvertPointFromScreen(gfx::Point* point) override;
  bool DrawsHandles() override;
  void OpenContextMenu(const gfx::Point& anchor) override;
  void DestroyTouchSelection() override;

  // ui::SimpleMenuModel::Delegate overrides:
  bool IsCommandIdChecked(int command_id) const override;
  bool IsCommandIdEnabled(int command_id) const override;
  bool GetAcceleratorForCommandId(int command_id,
                                  ui::Accelerator* accelerator) override;
  void ExecuteCommand(int command_id, int event_flags) override;

  // ui::TextInputClient overrides:
  void SetCompositionText(const ui::CompositionText& composition) override;
  void ConfirmCompositionText() override;
  void ClearCompositionText() override;
  void InsertText(const base::string16& text) override;
  void InsertChar(base::char16 ch, int flags) override;
  gfx::NativeWindow GetAttachedWindow() const override;
  ui::TextInputType GetTextInputType() const override;
  ui::TextInputMode GetTextInputMode() const override;
  int GetTextInputFlags() const override;
  bool CanComposeInline() const override;
  gfx::Rect GetCaretBounds() const override;
  bool GetCompositionCharacterBounds(uint32 index,
                                     gfx::Rect* rect) const override;
  bool HasCompositionText() const override;
  bool GetTextRange(gfx::Range* range) const override;
  bool GetCompositionTextRange(gfx::Range* range) const override;
  bool GetSelectionRange(gfx::Range* range) const override;
  bool SetSelectionRange(const gfx::Range& range) override;
  bool DeleteRange(const gfx::Range& range) override;
  bool GetTextFromRange(const gfx::Range& range,
                        base::string16* text) const override;
  void OnInputMethodChanged() override;
  bool ChangeTextDirectionAndLayoutAlignment(
      base::i18n::TextDirection direction) override;
  void ExtendSelectionAndDelete(size_t before, size_t after) override;
  void EnsureCaretInRect(const gfx::Rect& rect) override;
  void OnCandidateWindowShown() override;
  void OnCandidateWindowUpdated() override;
  void OnCandidateWindowHidden() override;
  bool IsEditingCommandEnabled(int command_id) override;
  void ExecuteEditingCommand(int command_id) override;

 protected:
  // Returns the TextfieldModel's text/cursor/selection rendering model.
  gfx::RenderText* GetRenderText() const;

  gfx::Point last_click_location() const { return last_click_location_; }

  // Get the text from the selection clipboard.
  virtual base::string16 GetSelectionClipboardText() const;

 private:
  friend class TextfieldTestApi;

  // Handles a request to change the value of this text field from software
  // using an accessibility API (typically automation software, screen readers
  // don't normally use this). Sets the value and clears the selection.
  void AccessibilitySetValue(const base::string16& new_value);

  // Updates the painted background color.
  void UpdateBackgroundColor();

  // Does necessary updates when the text and/or cursor position changes.
  void UpdateAfterChange(bool text_changed, bool cursor_changed);

  // A callback function to periodically update the cursor state.
  void UpdateCursor();

  // Repaint the cursor.
  void RepaintCursor();

  void PaintTextAndCursor(gfx::Canvas* canvas);

  // Helper function to call MoveCursorTo on the TextfieldModel.
  void MoveCursorTo(const gfx::Point& point, bool select);

  // Helper function to update the selection on a mouse drag.
  void SelectThroughLastDragLocation();

  // Convenience method to notify the InputMethod and TouchSelectionController.
  void OnCaretBoundsChanged();

  // Convenience method to call TextfieldController::OnBeforeUserAction();
  void OnBeforeUserAction();

  // Convenience method to call TextfieldController::OnAfterUserAction();
  void OnAfterUserAction();

  // Calls |model_->Cut()| and notifies TextfieldController on success.
  bool Cut();

  // Calls |model_->Copy()| and notifies TextfieldController on success.
  bool Copy();

  // Calls |model_->Paste()| and calls TextfieldController::ContentsChanged()
  // explicitly if paste succeeded.
  bool Paste();

  // Utility function to prepare the context menu.
  void UpdateContextMenu();

  // Tracks the mouse clicks for single/double/triple clicks.
  void TrackMouseClicks(const ui::MouseEvent& event);

  // Returns true if the current text input type allows access by the IME.
  bool ImeEditingAllowed() const;

  // Reveals the password character at |index| for a set duration.
  // If |index| is -1, the existing revealed character will be reset.
  void RevealPasswordChar(int index);

  void CreateTouchSelectionControllerAndNotifyIt();

  // Updates the selection clipboard to any non-empty text selection.
  void UpdateSelectionClipboard() const;

  // Pastes the selection clipboard for the specified mouse event.
  void PasteSelectionClipboard(const ui::MouseEvent& event);

  // The text model.
  scoped_ptr<TextfieldModel> model_;

  // This is the current listener for events from this Textfield.
  TextfieldController* controller_;

  // True if this Textfield cannot accept input and is read-only.
  bool read_only_;

  // The default number of average characters for the width of this text field.
  // This will be reported as the "desired size". Defaults to 0.
  int default_width_in_chars_;

  scoped_ptr<Painter> focus_painter_;

  // Flags indicating whether various system colors should be used, and if not,
  // what overriding color values should be used instead.
  bool use_default_text_color_;
  bool use_default_background_color_;
  bool use_default_selection_text_color_;
  bool use_default_selection_background_color_;
  SkColor text_color_;
  SkColor background_color_;
  SkColor selection_text_color_;
  SkColor selection_background_color_;

  // Text to display when empty.
  base::string16 placeholder_text_;

  // Placeholder text color.
  SkColor placeholder_text_color_;

  // The accessible name of the text field.
  base::string16 accessible_name_;

  // The input type of this text field.
  ui::TextInputType text_input_type_;

  // The duration and timer to reveal the last typed password character.
  base::TimeDelta password_reveal_duration_;
  base::OneShotTimer<Textfield> password_reveal_timer_;

  // Tracks whether a user action is being performed; i.e. OnBeforeUserAction()
  // has been called, but OnAfterUserAction() has not yet been called.
  bool performing_user_action_;

  // True if InputMethod::CancelComposition() should not be called.
  bool skip_input_method_cancel_composition_;

  // The text editing cursor repaint timer and visibility.
  base::RepeatingTimer<Textfield> cursor_repaint_timer_;
  bool cursor_visible_;

  // The drop cursor is a visual cue for where dragged text will be dropped.
  bool drop_cursor_visible_;
  gfx::SelectionModel drop_cursor_position_;

  // Is the user potentially dragging and dropping from this view?
  bool initiating_drag_;

  // A timer and point used to modify the selection when dragging.
  base::RepeatingTimer<Textfield> drag_selection_timer_;
  gfx::Point last_drag_location_;

  // State variables used to track double and triple clicks.
  size_t aggregated_clicks_;
  base::TimeDelta last_click_time_;
  gfx::Point last_click_location_;
  gfx::Range double_click_word_;

  scoped_ptr<ui::TouchEditingControllerDeprecated> touch_selection_controller_;

  // Used to track touch drag starting location and offset to enable touch
  // scrolling.
  gfx::Point drag_start_location_;
  int drag_start_display_offset_;

  // Tracks if touch editing handles are hidden because user has started
  // scrolling. If |true|, handles are shown after scrolling ends.
  bool touch_handles_hidden_due_to_scroll_;

  // Context menu related members.
  scoped_ptr<ui::SimpleMenuModel> context_menu_contents_;
  scoped_ptr<views::MenuRunner> context_menu_runner_;

  // Used to bind callback functions to this object.
  base::WeakPtrFactory<Textfield> weak_ptr_factory_;

  DISALLOW_COPY_AND_ASSIGN(Textfield);
};

}  // namespace views

#endif  // UI_VIEWS_CONTROLS_TEXTFIELD_TEXTFIELD_H_