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QdbtValidatingCell Class Reference
[Cell implementations]

The QdbtValidatingCell class represents a cell in a QdbtTabular object that can store strings. It provides the possibility to constrain input to a maximum allowed length and/or use a QValidator to validate the input. More...

#include <qdbtvalidatingcell.h>

Inheritance diagram for QdbtValidatingCell:

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Collaboration diagram for QdbtValidatingCell:

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List of all members.

Public Methods

 QdbtValidatingCell ()
 QdbtValidatingCell (const QdbtValidatingCell &)
 QdbtValidatingCell (const QString &, int=-1, const QValidator *=0, int=Qt::AlignLeft, bool=FALSE)
virtual ~QdbtValidatingCell ()
void setText (const QString &value)
virtual QString text () const
void setAlignment (int alignment)
int alignment () const
virtual int widthHint (const QFontMetrics &fm) const
virtual int heightHint (const QFontMetrics &fm) const
virtual const QColor & color (QdbtBaseTabular *) const
virtual const QColor & background (QdbtBaseTabular *) const
virtual void setEditable (bool state)
bool isEditable () const
virtual void paintFocus (QPainter *p, QdbtBaseTabular *t, const QRect &r, bool selected, bool editing=FALSE)
void rightButtonClicked (QdbtBaseTabular *tab, int row, int col) const

Protected Methods

virtual QWidget * editor (QdbtBaseTabular *) const
virtual void paint (QPainter *, QdbtBaseTabular *, const QRect &, bool, bool=FALSE)
virtual QRect getTextArea () const
virtual QRect getEditArea (int) const
QdbtBaseCell * clone (QdbtBaseTabular *) const
virtual bool beginEdit (QdbtBaseTabular *, int row, int col, const QRect cellGeometry) const
virtual bool acceptEdit (QdbtBaseTabular *, int row, int col)
virtual bool cancelEdit (QdbtBaseTabular *, int row, int col)
virtual bool mouseEvent (QdbtBaseTabular *, int row, int col, QMouseEvent *e, const QRect cellGeometry)
virtual bool keyEvent (QdbtBaseTabular *, int row, int col, QKeyEvent *e, const QRect cellGeometry)
virtual void setEditorEnabled (QdbtBaseTabular *, bool) const
virtual void moveEditor (QdbtBaseTabular *, const QRect cellGeometry) const
bool aboutToBeEdited (QdbtBaseTabular *) const
void notifyOnEditResult (QdbtBaseTabular *tab, int row, int col, int result, QString oldText)
QFont font (QdbtBaseTabular *) const
bool prepareEditor (QdbtBaseTabular *tab, const QRect &geom) const
bool cleanupEditor (QdbtBaseTabular *tab) const

Static Protected Attributes

int MASK_EDITABLE = 0x0001
int MASK_SELECTABLE = 0x0002
int MASK_SELECTED = 0x0004
int bw = 4

Detailed Description

The QdbtValidatingCell class represents a cell in a QdbtTabular object that can store strings. It provides the possibility to constrain input to a maximum allowed length and/or use a QValidator to validate the input.

The cell itself is not aware of its width and height, but can compute its preferred size given the font metrics that are used for the text.

The alignment of the text within the cell can be controlled using setAlignment().

Constructor & Destructor Documentation

QdbtValidatingCell::QdbtValidatingCell (    ) 
 

Constructs a cell with the following properties:

  • The cell has an empty string
  • The color of the text is not set (thus using the Foreground-Color or HilightedText of the Tabular's palette)
  • The background of the cell is not set (thus unding the Base-Color or Hilight of the Tabular's palette)
  • The cell's text is not editable.
  • The cell is not selected.
  • The cell is selectable.
  • The cell's text is aligned to the left.
  • Size of text input is not constrained
  • No validator is assigned

QdbtValidatingCell::QdbtValidatingCell (  const QdbtValidatingCell &    cell ) 
 

This constructor copy the supplied cell

QdbtValidatingCell::QdbtValidatingCell (  const QString &    value,
int    maxLen = -1,
const QValidator *    validator = 0,
int    alignment = Qt::AlignLeft,
bool    editing = FALSE
) 
 

Constructs a cell with the following properties:

  • Text for display is initialized to value.
  • The color of the text is not set (thus using the Foreground-Color or HilightedText of the Tabular's palette)
  • The background of the cell has the same color as the background of the table.
  • The number of characters allowed is constrained to maxLen. If maxLen equals -1, the number of characters is not constrained
  • The validator is set to validator. 0 is allowed for no validator
  • The text is aligned according to the value of alignment. Possible values are AlignLeft, AlignRight and AlignCenter.
  • The ability to edit a cell is set to editing.
  • The cell is not selected.
  • The cell is selectable.

QdbtValidatingCell::~QdbtValidatingCell (    )  [virtual]
 

The destructor does nothing

Member Function Documentation

bool QdbtBaseCell::aboutToBeEdited (  QdbtBaseTabular *    tab )  const [protected, inherited]
 

This function interacts with the table and clarifies, if a new editing session may be started. If this function returns FALSE, no edit session may be started currently.

See also:
beginEdit()

bool QdbtValidatingCell::acceptEdit (  QdbtBaseTabular *    tab,
int    row,
int    col
)  [protected, virtual]
 

After editing has been done (and e.g. Return/Enter has been pressed), this function evaluates if the modified cell content is acceptable (when a pattern for the cell's column has been set, this pattern is being matched) and notifies the user on the edit's outcome.

This function retreives the current value from the editor and stores it within the table's cell (if accepted)

Reimplemented from QdbtBaseCell.

int QdbtValidatingCell::alignment (    )  const [inline]
 

Returns the alignment currently set for the text within this cell

const QColor & QdbtBaseCell::background (  QdbtBaseTabular *    tab )  const [virtual, inherited]
 

This function computes the background color for a table's cell. This color is generated from the table-component's forground color, if it is existing. If not (e.g. if the pointer to the tabular tab is not supplied correctly), a default color or white is supplied.

Reimplemented in QdbtTableCell.

bool QdbtValidatingCell::beginEdit (  QdbtBaseTabular *    tab,
int    row,
int    col,
const QRect    cellGeometry
)  const [protected, virtual]
 

Begin a new edit session. For this purpose a line editor is being initialized and show at the place, that is being occupied by the table's cells at row, col with the geometry cellGeometry

Reimplemented from QdbtBaseCell.

bool QdbtValidatingCell::cancelEdit (  QdbtBaseTabular *    tab,
int    row,
int    col
)  [protected, virtual]
 

If an edit-session has to be canceled for any reason, the table will use this function to ask for cancellation of an edit-session. The edit-session should then be canceled if possible.

When cancelEdit() returns TRUE, the tabular expects that the cell editor has been reset and made invisible again before this function returns.

See also:
acceptEdit()

Reimplemented from QdbtBaseCell.

bool QdbtBaseCell::cleanupEditor (  QdbtBaseTabular *    tab )  const [protected, inherited]
 

This member cleans up a cell's editor and ensures that the editor is not visible any longer.

Parameters:
tab  The tabular, to which the cell belongs
Returns:
TRUE if the editor has been cleaned up correctly, FALSE otherwise. If this function returns FALSE, it has not take any actions.
Attention:
This function relies on the editor()-function to answer the correct cell editor widget.
See also:
prepareEditor()

QdbtBaseCell * QdbtValidatingCell::clone (  QdbtBaseTabular *    )  const [protected, virtual]
 

This abstract method is being used to produce a new instance with exactly the same internal state as the original object was. If is being used whenever a copy of a cell has to be produced, e.g. when changing cells within the tabular widget's table matrix.

For initializing the new cell properly, the context of the cell (the tabular widget, that it is located in) is being transfered to the clone() function.

Warning:
This function is virtually used as a virtual constructor. Please refer to the Prototype paragraph from Erich Gamma et. al, 'Design Patterns, Elements of Reusable Object-Oriented Software', Addison-Wesley, 1995 (a book definitely worth its price)

Implements QdbtBaseCell.

const QColor & QdbtBaseCell::color (  QdbtBaseTabular *    tab )  const [virtual, inherited]
 

This function computes the forground color for a table's cell. This color is generated from the table-component's forground color, if it is existing. If not (e.g. if the pointer to the tabular tab is not supplied correctly), a default color or black is supplied.

Reimplemented in QdbtTableCell.

QWidget * QdbtValidatingCell::editor (  QdbtBaseTabular *    tab )  const [protected, virtual]
 

This functions serves to determine the editor widget associated to a table cell. This function should be provided within a derived class, since the function determining if a tabular contains the keyboard focus relies on it. However it is safe to return 0, if no editor may be returned or even is only produced on demand.

Reimplemented from QdbtBaseCell.

QFont QdbtBaseCell::font (  QdbtBaseTabular *    tab )  const [protected, inherited]
 

Read the font, that has been set for the QdbtTabular Widget. This font should be used for all text-editor facilities.

Parameters:
tab  The context (tabular), with which the cell is used

QRect QdbtValidatingCell::getEditArea (  int    )  const [protected, virtual]
 

Returns the area inside the cell, where the edit focus may be placed. The coordinates of the rectangle are in pixels and relative to the cell. The top left of the cell has coordinates (0,0).

Same as getTextArea() for this cell type.

Reimplemented from QdbtBaseCell.

QRect QdbtValidatingCell::getTextArea (    )  const [protected, virtual]
 

Returns the area inside the cell, where the text is being drawn. The coordinates of the rectangle are in pixels and relative to the cell. The top left of the cell has coordinates (0,0).

Same as getEditArea() for this cell type.

Reimplemented from QdbtBaseCell.

int QdbtValidatingCell::heightHint (  const QFontMetrics &    fm )  const [virtual]
 

Returns the preferred height of the cell. The height is computet from the font metrics and incorporates border spacings.

See also:
widthHint().

Reimplemented from QdbtBaseCell.

bool QdbtBaseCell::isEditable (    )  const [inherited]
 

Returns TRUE if the cell may be edited by the user.

See also:
setEditable().

bool QdbtBaseCell::keyEvent (  QdbtBaseTabular *   ,
int    row,
int    col,
QKeyEvent *    e,
const QRect    cellGeometry
)  [protected, virtual, inherited]
 

This method is used to inform a table cell about a key press event. The cell receives its coordinates with the table's matrix as row, col, all information on the key pressed e as well as its current geometry cellGeometry in the coordinate system of the table's cell matrix.

If this method returns FALSE, the table will apply the normal 'keyboard' rules (cursor keys traverse the focus, etc). If the method returns TRUE, the table components assume, that anything necessary has already been taken care of.

Reimplemented in QdbtComboCell.

bool QdbtBaseCell::mouseEvent (  QdbtBaseTabular *   ,
int    row,
int    col,
QMouseEvent *    e,
const QRect    cellGeometry
)  [protected, virtual, inherited]
 

This method is used to inform a table cell about a mouse press event. The cell receives its coordinates with the table's matrix as row, col, the coordinates of the mouse click relative to the table's cell matrix as e as well as its current geometry cellGeometry in the coordinate system of the table's cell matrix.

If this method returns FALSE, the table will apply the normal 'editing' rules (center mousebutton will edit the cell). If the method returns TRUE, the table components assume, that anything necessary has already been taken care of.

Reimplemented in QdbtComboCell.

void QdbtBaseCell::moveEditor (  QdbtBaseTabular *    tab,
const QRect    geom
)  const [protected, virtual, inherited]
 

This method is called whenever a table cell is being edited and the table is repainted. The method should check if the geometry of handed over is the same as the geometry applied to the editor widget and - if not - should resize or move the editor widget to the correct position.

The default implementation determines the editor widget by calling editor() and moves it to the correct location.

void QdbtBaseCell::notifyOnEditResult (  QdbtBaseTabular *    tab,
int    row,
int    col,
int    result,
QString    oldText
)  [protected, inherited]
 

This function interacts with the tabular components and may be used to communicate the result of an edit session to the remaining programm parts.

void QdbtValidatingCell::paint (  QPainter *    p,
QdbtBaseTabular *    t,
const QRect &    r,
bool    selected,
bool    editing = FALSE
)  [protected, virtual]
 

Reimplemented for internal reasons; the API is not affected.

Reimplemented from QdbtBaseCell.

void QdbtBaseCell::paintFocus (  QPainter *    p,
QdbtBaseTabular *    t,
const QRect &    r,
bool    selected,
bool    editing = FALSE
)  [virtual, inherited]
 

This function is called whenever the cell's focus needs to be repainted. The width of the cell is w and the height is h is passed. To be able to interact with the tabular widget (e.g. for style support) that paints this cell, a pointer to it is passed to this function. The painter p automatically clips against the area of the cell.

Reimplemented in QdbtComboCell, and QdbtBorderlessComboCell.

bool QdbtBaseCell::prepareEditor (  QdbtBaseTabular *    tab,
const QRect &    geom
)  const [protected, inherited]
 

Prepare the cell's editor for the about-to-be-started edit session.

Parameters:
tab  The tabular, to which this cell belongs
geom  The cell (and thus the editor's) geometry
Returns:
TRUE, if the editor has been configured appropriately, FALSE otherwise. If this function returns FALSE, it has not take any actions.
Attention:
This function relies on the editor()-function to anser the correct cell editor widget.
See also:
cleanupEditor()

void QdbtBaseCell::rightButtonClicked (  QdbtBaseTabular *    tab,
int    row,
int    col
)  const [inherited]
 

This functions informs the user, that the right mouse buttons has been pressed on top of the cell in row row and col col. This method should be used within each of the editor widgets mapped on top of the table components, for the 'normal' cells this signal is begin generated automatically.

void QdbtValidatingCell::setAlignment (  int    alignment )  [inline]
 

Sets the alignment for displaying the text in this cell

void QdbtBaseCell::setEditable (  bool    state )  [virtual, inherited]
 

Sets whether or not the cell may be edited by the application user.

If state is TRUE the cell may be edited.

If state is FALSE the cell may not be edited.

See also:
isEditable().
Examples:
example1.cpp, example3.cpp, example4.cpp, and example5.cpp.

void QdbtBaseCell::setEditorEnabled (  QdbtBaseTabular *    tab,
bool    enable
)  const [protected, virtual, inherited]
 

This function serves to temporaryly disable/enable the editor widget, if there is any.

The default implementation determines the editor widget by calling editor() and disables or enables it according to enable.

void QdbtValidatingCell::setText (  const QString &    value )  [inline]
 

Sets the text of the cell to value

QString QdbtValidatingCell::text (    )  const [inline, virtual]
 

Returns the text currently represented by this cell

Reimplemented from QdbtBaseCell.

int QdbtValidatingCell::widthHint (  const QFontMetrics &    fm )  const [virtual]
 

Returns the preferred width of the cell. This is the actual cell's text's width including border spacings.

See also:
heightHint().

Reimplemented from QdbtBaseCell.

Member Data Documentation

QdbtBaseCell::bw = 4 [static, protected, inherited]
 

Default spacing value for tabular cells.

The documentation for this class was generated from the following files:
Generated on Mon Apr 22 12:22:06 2002 for QdbtTabular by doxygen1.2.15-20020421