/*
    Requires the Qt widget libraries, available at no cost at
    http://www.troll.no

    Copyright (C) 1997 Bernd Johannes Wuebben <wuebben@kde.org>
    Copyright (c) 1999 Preston Brown <pbrown@kde.org>
    Copyright (c) 1999 Mario Weilguni <mweilguni@kde.org>

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Library General Public
    License as published by the Free Software Foundation; either
    version 2 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Library General Public License for more details.

    You should have received a copy of the GNU Library General Public License
    along with this library; see the file COPYING.LIB.  If not, write to
    the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
    Boston, MA 02110-1301, USA.
*/
#ifndef K_FONT_CHOOSER_H
#define K_FONT_CHOOSER_H

#include <kdeui_export.h>
#include <QtGui/QWidget>

class QFont;
class QStringList;

/**
 * @short A font selection widget.
 *
 * While KFontChooser as an ordinary widget can be embedded in
 * custom dialogs and therefore is very flexible, in most cases
 * it is preferable to use the convenience functions in
 * KFontDialog.
 *
 * \image html kfontchooser.png "KDE Font Chooser Widget"
 *
 * @see KFontRequester
 *
 * @author Preston Brown <pbrown@kde.org>, Bernd Wuebben <wuebben@kde.org>
 */
class KDEUI_EXPORT KFontChooser : public QWidget
{
  Q_OBJECT
  Q_PROPERTY( QFont font READ font WRITE setFont USER true )

public:
    /**
     *  @li @p FamilyList - Identifies the family (leftmost) list.
     *  @li @p StyleList -  Identifies the style (center) list.
     *  @li @p SizeList -   Identifies the size (rightmost) list.
     */
    enum FontColumn { FamilyList=0x01, StyleList=0x02, SizeList=0x04};

    /**
     *  @li @p FontDiffFamily - Identifies a requested change in the font family.
     *  @li @p FontDiffStyle -  Identifies a requested change in the font style.
     *  @li @p FontDiffSize -   Identifies a requested change in the font size.
     */
    enum FontDiff { NoFontDiffFlags = 0,
                    FontDiffFamily = 1,
                    FontDiffStyle = 2,
                    FontDiffSize = 4,
                    AllFontDiffs = FontDiffFamily | FontDiffStyle | FontDiffSize };
    Q_DECLARE_FLAGS( FontDiffFlags, FontDiff )

    /**
     * @li @p FixedFontsOnly only show fixed fonts, excluding proportional fonts
     * @li @p DisplayFrame show a visual frame around the chooser
     * @li @p ShowDifferences display the font differences interfaces
     */
    enum DisplayFlag { NoDisplayFlags = 0,
                       FixedFontsOnly = 1,
                       DisplayFrame = 2,
                       ShowDifferences = 4 };
    Q_DECLARE_FLAGS( DisplayFlags, DisplayFlag )

  /**
   * Constructs a font picker widget.
   * It normally comes up with all font families present on the system; the
   * getFont method below does allow some more fine-tuning of the selection of fonts
   * that will be displayed in the dialog.
   * <p>Consider the following code snippet;
   * \code
   *    QStringList list;
   *    KFontChooser::getFontList(list, KFontChooser::SmoothScalableFonts);
   *    KFontChooser *chooseFont = new KFontChooser(0, NoDisplayFlags, list);
   * \endcode
   * <p>
   * The above creates a font chooser dialog with only SmoothScaleble fonts.
   *
   * @param parent The parent widget.
   * @param flags Defines how the font chooser is displayed. @see DisplayFlags
   * @param fontList A list of fonts to display, in XLFD format.  If
   *        no list is formatted, the internal KDE font list is used.
   *        If that has not been created, X is queried, and all fonts
   *        available on the system are displayed.
   * @param visibleListSize The minimum number of visible entries in the
   *        fontlists.
   * @param sizeIsRelativeState If not zero the widget will show a
   *        checkbox where the user may choose whether the font size
   *        is to be interpreted as relative size.
   *        Initial state of this checkbox will be set according to
   *        *sizeIsRelativeState, user choice may be retrieved by
   *        calling sizeIsRelative().
   */
  explicit KFontChooser( QWidget *parent = 0L,
                         const DisplayFlags& flags = DisplayFrame,
                         const QStringList &fontList = QStringList(),
                         int visibleListSize = 8,
                         Qt::CheckState *sizeIsRelativeState = 0L );

  /**
   * Destructs the font chooser.
   */
  virtual ~KFontChooser();

  /**
   * Enables or disable a font column in the chooser.
   *
   * Use this
   * function if your application does not need or supports all font
   * properties.
   *
   * @param column Specify the columns. An or'ed combination of
   *        @p FamilyList, @p StyleList and @p SizeList is possible.
   * @param state If @p false the columns are disabled.
   */
  void enableColumn( int column, bool state );

  /**
   * Sets the currently selected font in the chooser.
   *
   * @param font The font to select.
   * @param onlyFixed Readjust the font list to display only fixed
   *        width fonts if @p true, or vice-versa.
   */
  void setFont( const QFont &font, bool onlyFixed = false );

  /**
   * @return The bitmask corresponding to the attributes the user
   *         wishes to change.
   */
  FontDiffFlags fontDiffFlags() const;

  /**
   * @return The currently selected font in the chooser.
   */
  QFont font() const;

  /**
   * Sets the color to use in the preview.
   */
  void setColor( const QColor & col );

  /**
   * @return The color currently used in the preview (default: the text
   *         color of the active color group)
   */
  QColor color() const;

  /**
   * Sets the background color to use in the preview.
   */
  void setBackgroundColor( const QColor & col );

  /**
   * @return The background color currently used in the preview (default:
   *         the base color of the active colorgroup)
   */
  QColor backgroundColor() const;

  /**
   * Sets the state of the checkbox indicating whether the font size
   * is to be interpreted as relative size.
   * NOTE: If parameter sizeIsRelative was not set in the constructor
   *       of the widget this setting will be ignored.
   */
  void setSizeIsRelative( Qt::CheckState relative );

  /**
   * @return Whether the font size is to be interpreted as relative size
   *         (default: QButton:Off)
   */
  Qt::CheckState sizeIsRelative() const;


  /**
   * @return The current text in the sample text input area.
   */
  QString sampleText() const;

  /**
   * Sets the sample text.
   *
   * Normally you should not change this
   * text, but it can be better to do this if the default text is
   * too large for the edit area when using the default font of your
   * application.
   *
   * @param text The new sample text. The current will be removed.
   */
  void setSampleText( const QString &text );

  /**
   * Shows or hides the sample text box.
   *
   * @param visible Set it to true to show the box, to false to hide it.
   */
  void setSampleBoxVisible( bool visible );

  /**
   * The selection criteria for the font families shown in the dialog.
   *  @li @p FixedWidthFont when included only fixed-width fonts are returned.
   *        The fonts where the width of every character is equal.
   *  @li @p ScalableFont when included only scalable fonts are returned;
   *        certain configurations allow bitmap fonts to remain unscaled and
   *        thus these fonts have limited number of sizes.
   *  @li @p SmoothScalableFont when included only return smooth scalable fonts.
   *        this will return only non-bitmap fonts which are scalable to any size requested.
   *        Setting this option to true will mean the "scalable" flag is irrelavant.
   */
  enum FontListCriteria { FixedWidthFonts=0x01, ScalableFonts=0x02, SmoothScalableFonts=0x04 };

  /**
   * Creates a list of font strings.
   *
   * @param list The list is returned here.
   * @param fontListCriteria should contain all the restrictions for font selection as OR-ed values
   *        @see KFontChooser::FontListCriteria for the individual values
   */
  static void getFontList( QStringList &list, uint fontListCriteria);

  /**
   * Reimplemented for internal reasons.
   */
  virtual QSize sizeHint( void ) const;

Q_SIGNALS:
  /**
   * Emitted whenever the selected font changes.
   */
  void fontSelected( const QFont &font );

private:
    class Private;
    Private * const d;

    Q_DISABLE_COPY(KFontChooser)

    Q_PRIVATE_SLOT(d, void _k_toggled_checkbox())
    Q_PRIVATE_SLOT(d, void _k_family_chosen_slot(const QString&))
    Q_PRIVATE_SLOT(d, void _k_size_chosen_slot(const QString&))
    Q_PRIVATE_SLOT(d, void _k_style_chosen_slot(const QString&))
    Q_PRIVATE_SLOT(d, void _k_displaySample(const QFont &font))
    Q_PRIVATE_SLOT(d, void _k_showXLFDArea(bool))
    Q_PRIVATE_SLOT(d, void _k_size_value_slot(double))
};

Q_DECLARE_OPERATORS_FOR_FLAGS( KFontChooser::DisplayFlags )

#endif
