// This may look like C code, but it's really -*- C++ -*-

/*

 * Copyright (C) 2008 Emweb bv, Herent, Belgium.

 *

 * See the LICENSE file for terms of use.

 */

#ifndef WPUSHBUTTON_H_

#define WPUSHBUTTON_H_

#include <Wt/WAnchor.h>

#include <Wt/WFormWidget.h>

#include <Wt/WJavaScript.h>

#include <Wt/WLink.h>

#include <Wt/WText.h>

namespace Wt {

/*! \class WPushButton Wt/WPushButton.h Wt/WPushButton.h

 *  \brief A widget that represents a push button.

 *

 * To act on a button click, connect a slot to the clicked() signal.

 *

 * \if cpp

 * Usage example:

 * \code

 * // container is a WContainerWidget*

 * Wt::WPushButton *ok =

 *   container->addWidget(std::make_unique<Wt::WPushButton>("Okay"));

 * ok->clicked().connect(ok, &Wt::WPushButton::disable);

 * ok->clicked().connect(this, &MyClass::processData);

 * \endcode

 * \endif

 *

 * %WPushButton is an \link WWidget::setInline(bool) inline \endlink widget.

 *

 * <h3>CSS</h3>

 *

 * The widget corresponds to the HTML <tt>&lt;button&gt;</tt> tag (with some

 * exceptions in the bootstrap theme).

 */

class WT_API WPushButton : public WFormWidget

{

public:

  /*! \brief Creates a push button.

   */

  WPushButton();

  /*! \brief Creates a push button with given label text.

   *

   * The default text format is TextFormat::Plain.

   */

  WPushButton(const WString& text);

  /*! \brief Creates a push button with given label text.

   */

  WPushButton(const WString& text, TextFormat textFormat);

  virtual ~WPushButton();

  /*! \brief Sets the default property.

   *

   * This has only a functional meaning for a button in a dialog

   * footer, as it becomes associated with pressing 'enter' in the

   * dialog.

   *

   * A default button may be rendered in a different style, depending

   * on the theme.

   */

  void setDefault(bool enabled);

  /*! \brief Returns whether the button is a default button.

   *

   * \sa setDefault()

   */

  bool isDefault() const;

  /*! \brief Sets whether the button is checkable.

   *

   * A checkable button can be checked and unchecked, and clicking

   * will toggle between these two states.

   *

   * \sa setChecked(bool)

   */

  void setCheckable(bool checkable);

  /*! \brief Returns whether a button is checkable.

   *

   * \sa setCheckable()

   */

  bool isCheckable() const;

  /*! \brief Sets the button state.

   *

   * This is ignored for a button which is not checkable.

   *

   * This method does not emit one of the checked() or unChecked()

   * signals.

   *

   * \sa setCheckable(), setChecked(), setUnChecked()

   */

  void setChecked(bool checked);

  /*! \brief Checks the button.

   *

   * Does not emit the checked() signal.

   *

   * \sa setChecked(bool)

   */

  void setChecked();

  /*! \brief Unchecks the button.

   *

   * Does not emit the unChecked() signal.

   *

   * \sa setChecked(bool)

   */

  void setUnChecked();

  /*! \brief Returns the button state.

   *

   * \sa setChecked()

   */

  bool isChecked() const;

  /*! \brief Sets the button text.

   *

   * The default text format is Wt::TextFormat::Plain.

   *

   * When the current text format is Wt::TextFormat::XHTML, and \p text is

   * literal (not created using WString::tr()), it is parsed using an

   * XML parser which discards malicious tags and attributes

   * silently. When the parser encounters an XML parse error, the

   * textFormat is changed to Wt::TextFormat::Plain.

   * If \p text is not a literal, the same parser is applied only

   * when the text is resolved.

   *

   * Returns whether the text could be set using the current

   * textFormat. A return value of \c false indicates that the text

   * format was changed in order to be able to accept the new text.

   *

   * \sa setTextFormat()

   */

  bool setText(const WString& text);

  /*! \brief Returns the button text.

   *

   * \sa setText()

   */

  const WString& text() const { return text_.text; }

  /*! \brief Sets the text format.

   *

   * The textFormat controls how the string should be interpreted:

   * either as plain text, which is displayed literally, or as

   * XHTML-markup.

   *

   * When changing the textFormat to Wt::TextFormat::XHTML, and the

   * current text is literal (not created using WString::tr()), the

   * current text is parsed using an XML parser which discards

   * malicious tags and attributes silently. When the parser

   * encounters an XML parse error, the textFormat is left unchanged,

   * and this method returns false.

   *

   * Returns whether the textFormat could be set for the current text.

   *

   * The default format is Wt::TextFormat::Plain.

   */

  bool setTextFormat(TextFormat format);

  /*! \brief Returns the text format.

   *

   * \sa setTextFormat()

   */

  TextFormat textFormat() const { return text_.format; }

  /*! \brief Sets an icon.

   *

   * The icon is placed to the left of the text.

   */

  void setIcon(const WLink& link);

  /*! \brief Returns the icon.

   *

   * \sa setIcon()

   */

  WLink icon() const { return icon_; }

  /*! \brief Sets a destination link.

   *

   * This method can be used to make the button behave like a WAnchor

   * (or conversely, an anchor look like a button) and redirect to

   * another URL when clicked.

   *

   * The \p link may be to a URL, a resource, or an internal path.

   *

   * By default, a button does not link to an URL and you should

   * listen to the clicked() signal to react to a click event.

   *

   * \warning In Bootstrap theme, you should set a link before it's rendered

   *          since it commit's the button to be rendered as an anchor.

   *          (see also http://redmine.emweb.be/issues/1802).

   */

  void setLink(const WLink& link);

  /*! \brief Returns the destination link.

   *

   * \sa setLink()

   */

  const WLink& link() const { return linkState_.link; }

  /*! \brief Returns the current value.

   *

   * Returns an empty string, since a button has no value.

   */

  virtual WT_USTRING valueText() const override;

  /*! \brief Sets the current value.

   *

   * Has no effect, since a button has not value.

   */

  virtual void setValueText(const WT_USTRING& value) override;

  /*! \brief Links a popup menu to the button.

   *

   * When the button is clicked, the linked popup menu is shown.

   */

  void setMenu(std::unique_ptr<WPopupMenu> menu);

  /*! \brief Returns an associated popup menu.

   *

   * \sa setMenu()

   */

  WPopupMenu *menu() const { return popupMenu_.get(); }

  virtual void refresh() override;

  /*! \brief %Signal emitted when the button gets checked.

   *

   * This signal is emitted when the user checks the button.

   *

   * You can use the clicked() signal to react to any change of the

   * button state.

   *

   * \sa setCheckable()

   */

  EventSignal<>& checked();

  /*! \brief %Signal emitted when the button gets unchecked.

   *

   * This signal is emitted when the user unchecks the button.

   *

   * You can use the clicked() signal to react to any change of the

   * button state.

   *

   * \sa setCheckable()

   */

  EventSignal<>& unChecked();

  virtual bool setFirstFocus() override;

private:

  static const char *CHECKED_SIGNAL;

  static const char *UNCHECKED_SIGNAL;

  static const int BIT_TEXT_CHANGED = 0;

  static const int BIT_ICON_CHANGED = 1;

  static const int BIT_ICON_RENDERED = 2;

  static const int BIT_LINK_CHANGED = 3;

  static const int BIT_DEFAULT = 4;

  static const int BIT_IS_CHECKABLE = 5;

  static const int BIT_IS_CHECKED = 6;

  static const int BIT_CHECKED_CHANGED = 7;

  WAnchor::LinkState linkState_;

  WText::RichText text_;

  WLink          icon_;

  std::bitset<8> flags_;

  std::unique_ptr<WPopupMenu> popupMenu_;

protected:

  virtual void updateDom(DomElement& element, bool all) override;

  virtual DomElementType domElementType() const override;

  virtual void propagateRenderOk(bool deep) override;

  virtual void getDomChanges(std::vector<DomElement *>& result,

                             WApplication *app) override;

  virtual void propagateSetEnabled(bool enabled) override;

  virtual void enableAjax() override;

private:

  void doRedirect();

  void resourceChanged();

  void renderHRef(DomElement& href);

  void toggled();

};

}

#endif // WPUSHBUTTON_H_