/*=========================================================================

  Library:   CTK

  Copyright (c) Kitware Inc.

  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at

      http://www.apache.org/licenses/LICENSE-2.0.txt

  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.

=========================================================================*/

#ifndef __ctkCollapsibleButton_h
#define __ctkCollapsibleButton_h

// Qt includes
#include <QAbstractButton>
#include <QFrame>

// CTK includes
#include <ctkPimpl.h>
#include "ctkWidgetsExport.h"

class ctkCollapsibleButtonPrivate;
class QStyleOptionButton;

/// \ingroup Widgets
/// A collapsible button that shows/hides its children depending on its
/// checked/collapsed property.
/// Warning: &lt;old behavior&gt; As ctkCollapsibleButton forces the Visiblity of its children to
/// true when it get expanded, any child Visibility property is lost. All the widgets
/// will then be visible. To avoid this behavior, use an intermediate widget that
/// contains all the children (they would become grandchildren and their Visibility property
/// will remain relative to their parent, ctkCollapsibleButton's unique child widget.&lt;/old behavior&gt;
/// Note: The user QAbstractButton::icon is not visible (it's placeholder is used to display the
/// collapsible state
class CTK_WIDGETS_EXPORT ctkCollapsibleButton : public QAbstractButton
{
  Q_OBJECT
  Q_PROPERTY(bool collapsed READ collapsed WRITE setCollapsed NOTIFY contentsCollapsed)
  /// This property holds the height in pixels of the contents (excludes the button)
  /// when the button is collapsed.
  /// 14 pixels by default (same as ctkCollapsibleGroupBox)
  Q_PROPERTY(int collapsedHeight READ collapsedHeight WRITE setCollapsedHeight)

  Q_PROPERTY(QFrame::Shape contentsFrameShape READ contentsFrameShape WRITE setContentsFrameShape)
  Q_PROPERTY(QFrame::Shadow contentsFrameShadow READ contentsFrameShadow WRITE setContentsFrameShadow)
  Q_PROPERTY(int contentsLineWidth READ contentsLineWidth WRITE setContentsLineWidth)
  Q_PROPERTY(int contentsMidLineWidth READ contentsMidLineWidth WRITE setContentsMidLineWidth)

  Q_PROPERTY(Qt::Alignment buttonTextAlignment READ buttonTextAlignment WRITE setButtonTextAlignment)
  Q_PROPERTY(Qt::Alignment indicatorAlignment READ indicatorAlignment WRITE setIndicatorAlignment)

public:
  ctkCollapsibleButton(QWidget *parent = 0);
  ctkCollapsibleButton(const QString& text, QWidget *parent = 0);
  virtual ~ctkCollapsibleButton();

  /// 
  /// Property that describes if the widget is collapsed or not.
  /// When collapsed, the children are invisible and the widget
  /// has a sized defined by CollapsedHeight
  void setCollapsed(bool);
  bool collapsed()const;

  ///
  /// \todo resize the widget when setting the new height
  void setCollapsedHeight(int heightInPixels);
  int collapsedHeight()const;

  /// 
  /// Set the frame shape of the contents
  /// Hint: StyledPanel is probably the shape you are looking for
  QFrame::Shape contentsFrameShape() const;
  void setContentsFrameShape(QFrame::Shape);

  /// 
  /// Set the frame shadow of the contents
  /// Hint: Raised is probably the shadow you are looking for
  QFrame::Shadow contentsFrameShadow() const;
  void setContentsFrameShadow(QFrame::Shadow);

  /// 
  /// Set the line width of the frame around the contents
  int contentsLineWidth() const;
  void setContentsLineWidth(int);

  /// 
  /// Set the mid line width of the frame around the contents
  int contentsMidLineWidth() const;
  void setContentsMidLineWidth(int);

  ///
  /// Set the alignment of the text on the button,
  /// Qt::AlignLeft|Qt::AlignVCenter by default.
  void setButtonTextAlignment(Qt::Alignment textAlignment);
  Qt::Alignment buttonTextAlignment()const;

  ///
  /// Set the alignment of the indicator (arrow) on the button,
  /// Qt::AlignLeft|Qt::AlignVCenter by default.
  void setIndicatorAlignment(Qt::Alignment indicatorAlignment);
  Qt::Alignment indicatorAlignment()const;

  /// 
  /// Reimplemented for internal reasons
  virtual QSize minimumSizeHint()const;

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

  /// Reimplemented to update the size of the button in case of font/style
  /// change
  virtual bool event(QEvent* event);

  /// Reimplemented for internal reasons
  /// Catch when a child widget's visibility is externally changed
  virtual bool eventFilter(QObject* child, QEvent* e);
  
  /// Reimplemented for internal reasons
  /// Don't process Show/Hide events of children when it is
  /// ctkCollapsibleButton that generate them.
  virtual void setVisible(bool);
Q_SIGNALS:
  /// 
  /// Signal emitted when the widget is collapsed or expanded.
  /// See signal toggled(bool) for the opposite.
  void contentsCollapsed(bool);

protected Q_SLOTS:
  /// 
  /// Perform the collapse.
  virtual void collapse(bool c);
  virtual void onToggled(bool clicked = false);

protected:
  virtual void paintEvent(QPaintEvent*);
  //virtual void mousePressEvent(QMouseEvent* event);
  //virtual void mouseReleaseEvent(QMouseEvent* event);
  virtual void childEvent(QChildEvent* c);

  virtual bool hitButton(const QPoint & pos) const;
  /// Compute the size hint of the head button only. The sizehint depends on the text.
  virtual QSize buttonSizeHint() const;

  /// Initialize option with the values from this ctkCollapsibleButton.
  /// This method is useful for subclasses when they need a QStyleOptionButton, 
  /// but don't want to fill in all the information themselves.
  virtual void initStyleOption(QStyleOptionButton* option)const;

protected:
  QScopedPointer<ctkCollapsibleButtonPrivate> d_ptr;

private:
  Q_DECLARE_PRIVATE(ctkCollapsibleButton);
  Q_DISABLE_COPY(ctkCollapsibleButton);
};

#endif