ktreelist.h

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/* qktstreelist.h
-------------------------------------------------------------------
$Revision: 1.1 $
$Date: 2003/09/08 19:42:12 $
  
KTreeList class declaration

Copyright (C) 1996 Keith Brown and KtSoft

This program 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 program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABLILITY 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 program; if
not, write to the Free Software Foundation, Inc, 675 Mass Ave, 
Cambridge, MA 02139, USA.

-------------------------------------------------------------------
*/

#ifndef KTREE_LIST_H
#define KTREE_LIST_H

#include <qapplication.h>       // used for QApplication::closingDown()
#include <qkeycode.h>           // used for keyboard interface
#include <qpainter.h>		// used to paint items
#include <qpixmap.h>		// used in items
#include <qstack.h>		// used to specify tree paths
#include <qstring.h>		// used in items
#include <qtableview.h>		// base class for widget

// use stack of strings to represent path information
typedef QStack<QString> KPath;

class KTreeList;		// forward declaration

/** Items for the KTreeList widget */
class KTreeListItem
{
public:
  /**
    Item constructor. While text defaults to a null pointer, and the item
    can be constructed this way, the text has to be non-null when the
    item is added to the tree, or it will not be inserted.
    */
  KTreeListItem(const char *theText = 0, 
				const QPixmap *thePixmap = 0); // text can not be null when added to the list!

  virtual ~KTreeListItem();

  void appendChild(KTreeListItem *newChild);

  virtual QRect boundingRect(const QFontMetrics& fm) const;

  /**
	Returns a pointer to the child item at the given index in this item's
	sub tree, or 0 if not found.
	*/	
  KTreeListItem *childAt(int index);

  /**
	Returns the number of child items in this item's sub tree.
	*/
  uint childCount() const;

  /**
	Returns the index in this items sub tree of the given item or -1 if
	not found.
	*/
  int childIndex(KTreeListItem *child);

  bool drawExpandButton() const;

  bool drawText() const;

  bool drawTree() const;

  bool expandButtonClicked(const QPoint& coord) const;

  int getBranch() const;

  /**
	Returns a pointer to the first child item in this item's sub tree, or
	0 if none.
	*/
  KTreeListItem *getChild();

  int getIndent() const;

  /**
	Returns a pointer to the parent of this item, or 0 if none.
	*/
  KTreeListItem *getParent();

  /**
	Returns a pointer to this item's pixmap. If there is no pixmap
	associated with this item, it will return a pointer to a valid, null
	QPixmap.
	*/
  const QPixmap *getPixmap() const;

  /**
	Returns a pointer to the next item in the same branch below this one,
	or 0 if none.
	*/
  KTreeListItem *getSibling();

  /**
	Returns a pointer to this item's text.
	*/
  const char *getText() const;

  /**
	Indicates whether this item has any children.
	*/
  bool hasChild() const;

  /**
	Indicates whether this item has a parent.
	*/
  bool hasParent() const;

  /**
	Indicates whether this item has an item in the same branch below it.
	*/
  bool hasSibling() const;

  virtual int height(const KTreeList *theOwner) const;

  void insertChild(int index,
				   KTreeListItem *newItem);

  bool isExpanded() const;

  virtual void paint(QPainter *p, 
					 const QColorGroup& cg, 
					 bool highlighted);

  void removeChild(KTreeListItem *child);

  void setBranch(int level);

  void setChild(KTreeListItem *newChild);

  void setDrawExpandButton(bool doit);

  void setDrawText(bool doit);

  void setDrawTree(bool doit);

  void setExpanded(bool is);

  void setIndent(int value);

  void setParent(KTreeListItem *newParent);

  /**
	Sets the item pixmap to the given pixmap.
	*/
  void setPixmap(const QPixmap *pm);

  void setSibling(KTreeListItem *newSibling);

  /**
	Sets the item text to the given item.
	*/
  void setText(const char *t);

  virtual QRect textBoundingRect(const QFontMetrics& fm) const;

  virtual QRect itemBoundingRect(const QFontMetrics& fm) const;

  virtual int width(const KTreeList *theOwner) const;

protected:
  virtual int itemHeight(const QFontMetrics& fm) const;
  virtual int itemWidth(const QFontMetrics& fm) const;
private:
  int branch;
  int indent;
  int numChildren;
  bool doExpandButton;
  bool expanded;
  bool doTree;
  bool doText;
  QRect expandButton;
  KTreeListItem *child;
  KTreeListItem *parent;
  KTreeListItem *sibling;
  QPixmap pixmap;
  QString text;
};

// easier declarations of function prototypes for forEvery type functions
typedef bool (KTreeList::*KForEveryM)
  (KTreeListItem *, void *);
typedef bool (*KForEvery)
  (KTreeListItem *, void *);

struct KItemSearchInfo {
  int count;
  int index;
  KTreeListItem *foundItem;
  KItemSearchInfo() : count(0), index(0), foundItem(0) {}
};

/** 
  A collapsible treelist widget.

  1. Introduction
  2. Features
  3. Installation
  4. Public interface

  1. Introduction
  ================================================================================

  KTreeList is a class inherited from QTableView in the Qt user interface
  library. It provides a way to display hierarchical data in a single-inheritance
  tree, similar to tree controls in Microsoft Windows and other GUI's. It is most
  suitable for directory trees or outlines, but I'm sure other uses will come to
  mind. Frankly, it was designed mostly with the above two functions in mind, but
  I have tried to make it as flexible as I know how to make it easy to adapt to
  other uses. 

  In case of problems, I encourage you to read all of the other documentation
  files in this package before contacting me  as you may find the answer to your
  question in one of them. Also read the source code if you have time. I have
  tried to comment it adequately and make the source understandable.

  2. Features
  ================================================================================

  * Displays both text and optional pixmap supplied by the programmer. A support
  class, KTreeListItem, can be inherited and modified to draw items as needed
  by the programmer.

  * The list items can be returned by index or logical path and the tree
  navigated by parent, child or sibling references contained in them. Also,
  item information such as text, pixmap, branch level can be obtained.
  
  * Items can be inserted, changed and removed either by index in the visible
  structure, or by logical paths through the tree hierarchy. 

  * The logical path through the tree for any item can be obtained with the index
  of the item.

  * Tree structure display and expanding/collapsing of sub-trees is handled with
  no intervention from the programmer.
  
  * entire tree can be expanded or collapsed to a specified sub-level (handy for
  outline views)
  
  * Configuration as follows:

  enable/disable item text display (if you only want to display pixmaps)
  
  enable/disable drawing of expand/collapse button
  
  enable/disable drawing of tree structure
  
  * Keyboard support as follows:

  up/down arrows move the highlight appropriately and scroll the list an item at
  a time, if necessary
  
  pgup/pgdn move the highlight a 'page' up or down as applicable and scroll the
  view
  
  +/- keys expand/collapse the highlighted item if it appropriate
  
  enter key selects the highlighted item
  
  * Mouse support as follows:

  left click on item highlights it
  
  left click on an item "hot button" expands or collapses its sub-tree, as
  applicable
  
  double click on item selects it
  
  normal scrolling functions in conjunction with scrollbars if present

  2nd scrolling with the middle mouse button: pressing MMB inserts a
  rubberband, showing which part of the whole tree is currently visible.
  moving the mouse will scroll the visible part
  
  * Signals/Slots

  signal void highlighted(int) - emitted when an item in the tree is
  highlighted; sends the index of the item
  
  signal void selected(int) - emitted when an item in the tree is
  selected; sends the index of the item
  
  signal void expanded(int) - emitted when an item in the tree is expanded;
  sends the index of the item
  
  signal void collpased(int) - emitted when an item in the tree is collapsed;
  sends the index of the item
  */
class KTreeList : public QTableView
{
  Q_OBJECT
public:
  /**
	Widget contructor. Passes all parameters on to base QTableView, and
	does not use them directly. Does internal initialization, sets the
	current item to -1, and sets default values for scroll bars (both
	auto) and grid snap (snap to grid vertically).
	*/
  KTreeList(QWidget *parent = 0, 
			const char *name = 0,
			WFlags f = 0);

  virtual ~KTreeList();

  /**
	Adds a new item to the tree with the given text and pixmap as a child
	of the item currently at the given index. If the current item already
	has children, the new item is appended below them.
	*/
  void addChildItem(const char *theText,
					const QPixmap *thePixmap,
					int index);

  /**
	Same as above except parent item is specified by path.
	*/
  void addChildItem(const char *theText,
					const QPixmap *thePixmap,
					const KPath *thePath); 

  /**
	Adds the given item as a child of the item currently at the given
	index. If the current item already has children, the new item is
	appended below them.
	*/
  void addChildItem(KTreeListItem *newItem,
					int index);

  /**
	Same as above except parent item is specified by path.
	*/
  void addChildItem(KTreeListItem *newItem,
					const KPath *thePath);                                                             
  /**
	Returns a bool value indicating whether the list will display a
	horizontal scrollbar if one of the displayed items is wider than can
	be displayed at the current width of the view.
	*/
  bool autoBottomScrollBar() const;

  /**
	Returns a bool value indicating whether the list will display a
	vertical scrollbar if the number of displayed items is more than can
	be displayed at the current height of the view.
	*/
  bool autoScrollBar() const;

  /**
	Returns a bool value indicating whether the list will update
	immediately on changing the state of the widget in some way.
	*/
  bool autoUpdate() const;

  /**
	Returns a bool value indicating whether the list has currently has a
	horizontal scroll bar.