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TQTableItem Class Reference
[table module]

The TQTableItem class provides the cell content for TQTable cells. More...

#include <ntqtable.h>

Inherits TQt.

Inherited by TQComboTableItem and TQCheckTableItem.

List of all member functions.

Public Members

Detailed Description

The TQTableItem class provides the cell content for TQTable cells.

For many applications TQTableItems are ideal for presenting and editing the contents of TQTable cells. In situations where you need to create very large tables you may prefer an alternative approach to using TQTableItems: see the notes on large tables.

A TQTableItem contains a cell's data, by default, a string and a pixmap. The table item also holds the cell's display size and how the data should be aligned. The table item specifies the cell's EditType and the editor used for in-place editing (by default a TQLineEdit). If you want checkboxes use TQCheckTableItem, and if you want comboboxes use TQComboTableItem. The EditType (set in the constructor) determines whether the cell's contents may be edited.

If a pixmap is specified it is displayed to the left of any text. You can change the text or pixmap with setText() and setPixmap() respectively. For text you can use setWordWrap().

When sorting table items the key() function is used; by default this returns the table item's text(). Reimplement key() to customize how your table items will sort.

Table items are inserted into a table using TQTable::setItem(). If you insert an item into a cell that already contains a table item the original item will be deleted.

Example: 

    for ( int row = 0; row < table->numRows(); row++ ) {
        for ( int col = 0; col < table->numCols(); col++ ) {
            table->setItem( row, col,
                new TQTableItem( table, TQTableItem::WhenCurrent, TQString::number( row * col ) ) );
        }
    }

You can move a table item from one cell to another, in the same or a different table, using TQTable::takeItem() and TQTable::setItem() but see also TQTable::swapCells().

Table items can be deleted with delete in the standard way; the table and cell will be updated accordingly.

Note, that if you have a table item that is not currently in a table then anything you do to that item other than insert it into a table will result in undefined behaviour.

Reimplement createEditor() and setContentFromEditor() if you want to use your own widget instead of a TQLineEdit for editing cell contents. Reimplement paint() if you want to display custom content.

It is important to ensure that your custom widget can accept the keyboard focus, so that the user can use the tab key to navigate the table as normal. Therefore, if the widget returned by createEditor() does not itself accept the keyboard focus, it is necessary to nominate a child widget to do so on its behalf. For example, a TQHBox with two child TQLineEdit widgets may use one of them to accept the keyboard focus: 

    TQWidget* MyTableItem::createEditor() const
    {
        TQHBox* hbox = new TQHBox( table()->viewport() );
        hbox->setFocusProxy(new TQLineEdit( hbox ));
        new TQLineEdit( hbox );
        return hbox;
    }

By default, table items may be replaced by new TQTableItems during the lifetime of a TQTable. Therefore, if you create your own subclass of TQTableItem, and you want to ensure that this does not happen, you must call setReplaceable(FALSE) in the constructor of your subclass.

Table Items

See also TQCheckTableItem, TQComboTableItem, and Advanced Widgets.

Member Type Documentation

TQTableItem::EditType

This enum is used to define whether a cell is editable or read-only (in conjunction with other settings), and how the cell should be displayed.

Using this EditType ensures that the editor created with createEditor() (by default a TQLineEdit) is always visible. This has implications for the alignment of the content: the default editor aligns everything (even numbers) to the left whilst numerical values in the cell are by default aligned to the right.

If a cell with the edit type Always looks misaligned you could reimplement createEditor() for these items.

The OnTyping edit type is the default when TQTableItem objects are created by the convenience functions TQTable::setText() and TQTable::setPixmap().

The cell is actually editable only if TQTable::isRowReadOnly() is FALSE for its row, TQTable::isColumnReadOnly() is FALSE for its column, and TQTable::isReadOnly() is FALSE.

TQComboTableItems have an isEditable() property. This property is used to indicate whether the user may enter their own text or are restricted to choosing one of the choices in the list. TQComboTableItems may be interacted with only if they are editable in accordance with their EditType as described above.

Member Function Documentation

TQTableItem::TQTableItem ( TQTable * table, EditType et )

Creates a table item that is a child of table table with no text. The item has the EditType et.

The table item will use a TQLineEdit for its editor, will not word-wrap and will occupy a single cell. Insert the table item into a table with TQTable::setItem().

The table takes ownership of the table item, so a table item should not be inserted into more than one table at a time.

TQTableItem::TQTableItem ( TQTable * table, EditType et, const TQString & text )

Creates a table item that is a child of table table with text text. The item has the EditType et.

The table item will use a TQLineEdit for its editor, will not word-wrap and will occupy a single cell. Insert the table item into a table with TQTable::setItem().

The table takes ownership of the table item, so a table item should not be inserted into more than one table at a time.

TQTableItem::TQTableItem ( TQTable * table, EditType et, const TQString & text, const TQPixmap & p )

Creates a table item that is a child of table table with text text and pixmap p. The item has the EditType et.

The table item will display the pixmap to the left of the text. It will use a TQLineEdit for editing the text, will not word-wrap and will occupy a single cell. Insert the table item into a table with TQTable::setItem().

The table takes ownership of the table item, so a table item should not be inserted in more than one table at a time.

TQTableItem::~TQTableItem () [virtual]

The destructor deletes this item and frees all allocated resources.

If the table item is in a table (i.e. was inserted with setItem()), it will be removed from the table and the cell it occupied.

int TQTableItem::alignment () const [virtual]

The alignment function returns how the text contents of the cell are aligned when drawn. The default implementation aligns numbers to the right and any other text to the left.

See also TQt::AlignmentFlags.

int TQTableItem::col () const

Returns the column where the table item is located. If the cell spans multiple columns, this function returns the left-most column.

See also row() and setCol().

Example: table/bigtable/main.cpp.

int TQTableItem::colSpan () const

Returns the column span of the table item, usually 1.

See also setSpan() and rowSpan().

TQWidget * TQTableItem::createEditor () const [virtual]

This virtual function creates an editor which the user can interact with to edit the cell's contents. The default implementation creates a TQLineEdit.

If the function returns 0, the cell is read-only.

The returned widget should preferably be invisible, ideally with TQTable::viewport() as parent.

If you reimplement this function you'll almost certainly need to reimplement setContentFromEditor(), and may need to reimplement sizeHint(). 

    TQWidget *ComboItem::createEditor() const
    {
        // create an editor - a combobox in our case
        ( (ComboItem*)this )->cb = new TQComboBox( table()->viewport() );
        TQObject::connect( cb, TQ_SIGNAL( activated( int ) ), table(), TQ_SLOT( doValueChanged() ) );
        cb->insertItem( "Yes" );
        cb->insertItem( "No" );
        // and initialize it
        cb->setCurrentItem( text() == "No" ? 1 : 0 );
        return cb;

See also TQTable::createEditor(), setContentFromEditor(), TQTable::viewport(), and setReplaceable().

Example: table/statistics/statistics.cpp.

EditType TQTableItem::editType () const

Returns the table item's edit type.

This is set when the table item is constructed.

See also EditType and TQTableItem().

bool TQTableItem::isEnabled () const

Returns TRUE if the table item is enabled; otherwise returns FALSE.

See also setEnabled().

bool TQTableItem::isReplaceable () const

This function returns whether the contents of the cell may be replaced with the contents of another table item. Regardless of this setting, table items that span more than one cell may not have their contents replaced by another table item.

(This differs from EditType because EditType is concerned with whether the user is able to change the contents of a cell.)

See also setReplaceable() and EditType.

TQString TQTableItem::key () const [virtual]

This virtual function returns the key that should be used for sorting. The default implementation returns the text() of the relevant item.

See also TQTable::sorting.

void TQTableItem::paint ( TQPainter * p, const TQColorGroup & cg, const TQRect & cr, bool selected ) [virtual]

This virtual function is used to paint the contents of an item using the painter p in the rectangular area cr using the color group cg.

If selected is TRUE the cell is displayed in a way that indicates that it is highlighted.

You don't usually need to use this function but if you want to draw custom content in a cell you will need to reimplement it.

The painter passed to this function is translated so that 0, 0 is the top-left corner of the item that is being painted.

Note that the painter is not clipped by default in order to get maximum efficiency. If you want clipping, use 

    p->setClipRect( table()->cellRect(row, col), TQPainter::ClipPainter );
    //... your drawing code
    p->setClipping( FALSE );

Example: table/statistics/statistics.cpp.

TQPixmap TQTableItem::pixmap () const [virtual]

Returns the table item's pixmap or a null pixmap if no pixmap has been set.

See also setPixmap() and text().

int TQTableItem::row () const

Returns the row where the table item is located. If the cell spans multiple rows, this function returns the top-most row.

See also col() and setRow().

Example: table/bigtable/main.cpp.

int TQTableItem::rowSpan () const

Returns the row span of the table item, usually 1.

See also setSpan() and colSpan().

int TQTableItem::rtti () const [virtual]

Returns the Run Time Type Identification value for this table item which for TQTableItems is 0.

When you create subclasses based on TQTableItem make sure that each subclass returns a unique rtti() value. It is advisable to use values greater than 1000, preferably large random numbers, to allow for extensions to this class.

See also TQCheckTableItem::rtti() and TQComboTableItem::rtti().

Reimplemented in TQComboTableItem and TQCheckTableItem.

void TQTableItem::setCol ( int c ) [virtual]

Sets column c as the table item's column. Usually you will not need to call this function.

If the cell spans multiple columns, this function sets the left-most column and retains the width of the multi-cell table item.

See also col(), setRow(), and colSpan().

void TQTableItem::setContentFromEditor ( TQWidget * w ) [virtual]

Whenever the content of a cell has been edited by the editor w, TQTable calls this virtual function to copy the new values into the TQTableItem.

If you reimplement createEditor() and return something that is not a TQLineEdit you will need to reimplement this function. 

    void ComboItem::setContentFromEditor( TQWidget *w )
    {
        // the user changed the value of the combobox, so synchronize the
        // value of the item (its text), with the value of the combobox
        if ( w->inherits( "TQComboBox" ) )
            setText( ( (TQComboBox*)w )->currentText() );
        else
            TQTableItem::setContentFromEditor( w );

See also TQTable::setCellContentFromEditor().

Example: table/statistics/statistics.cpp.

void TQTableItem::setEnabled ( bool b ) [virtual]

If b is TRUE, the table item is enabled; if b is FALSE the table item is disabled.

A disabled item doesn't respond to user interaction.

See also isEnabled().

void TQTableItem::setPixmap ( const TQPixmap & p ) [virtual]

Sets pixmap p to be this item's pixmap.

Note that setPixmap() does not update the cell the table item belongs to. Use TQTable::updateCell() to repaint the cell's contents.

For TQComboTableItems and TQCheckTableItems this function has no visible effect.

See also TQTable::setPixmap(), pixmap(), and setText().

void TQTableItem::setReplaceable ( bool b ) [virtual]

If b is TRUE it is acceptable to replace the contents of the cell with the contents of another TQTableItem. If b is FALSE the contents of the cell may not be replaced by the contents of another table item. Table items that span more than one cell may not have their contents replaced by another table item.

(This differs from EditType because EditType is concerned with whether the user is able to change the contents of a cell.)

See also isReplaceable().

void TQTableItem::setRow ( int r ) [virtual]

Sets row r as the table item's row. Usually you do not need to call this function.

If the cell spans multiple rows, this function sets the top row and retains the height of the multi-cell table item.

See also row(), setCol(), and rowSpan().

void TQTableItem::setSpan ( int rs, int cs ) [virtual]

Changes the extent of the TQTableItem so that it spans multiple cells covering rs rows and cs columns. The top left cell is the original cell.

Warning: This function only works if the item has already been inserted into the table using e.g. TQTable::setItem(). This function also checks to make sure if rs and cs are within the bounds of the table and returns without changing the span if they are not. In addition swapping, inserting or removing rows and columns that cross TQTableItems spanning more than one cell is not supported.

See also rowSpan() and colSpan().

void TQTableItem::setText ( const TQString & str ) [virtual]

Changes the table item's text to str.

Note that setText() does not update the cell the table item belongs to. Use TQTable::updateCell() to repaint the cell's contents.

See also TQTable::setText(), text(), setPixmap(), and TQTable::updateCell().

Example: table/statistics/statistics.cpp.

void TQTableItem::setWordWrap ( bool b ) [virtual]

If b is TRUE, the cell's text will be wrapped over multiple lines, when necessary, to fit the width of the cell; otherwise the text will be written as a single line.

See also wordWrap(), TQTable::adjustColumn(), and TQTable::setColumnStretchable().

TQSize TQTableItem::sizeHint () const [virtual]

This virtual function returns the size a cell needs to show its entire content.

If you subclass TQTableItem you will often need to reimplement this function.

TQTable * TQTableItem::table () const

Returns the TQTable the table item belongs to.

See also TQTable::setItem() and TQTableItem().

TQString TQTableItem::text () const [virtual]

Returns the text of the table item or TQString::null if there is no text.

To ensure that the current value of the editor is returned, setContentFromEditor() is called:

  1. if the editMode() is Always, or
  2. if editMode() is not Always but the editor of the cell is active and the editor is not a TQLineEdit.

This means that text() returns the original text value of the item if the editor is a line edit, until the user commits an edit (e.g. by pressing Enter or Tab) in which case the new text is returned. For other editors (e.g. a combobox) setContentFromEditor() is always called so the currently display value is the one returned.

See also setText() and pixmap().

bool TQTableItem::wordWrap () const

Returns TRUE if word wrap is enabled for the cell; otherwise returns FALSE.

See also setWordWrap().

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TQt 3.3.8