How to customize a listbox
Article Metadata
Developers may want to customize a list box according to their requirements. An example of such customization would be to remove the dotted column line from a double style list box.
Solution
Override the existing list box and item drawer methods by providing a custom implementation.
Below is a simplified example for customizing a double number style list box.
Header File
class CDSListItemDrawer : public CFormattedCellListBoxItemDrawer
{
public:
CDSListItemDrawer( MTextListBoxModel* aTextListBoxModel,
const CFont* aFont,
CFormattedCellListBoxData* aFormattedCellData );
void DrawItemText( TInt aItemIndex, const TRect &aActualItemRect,
TBool aItemIsCurrent, TBool aViewIsEmphasized,
TBool aItemIsSelected) const;
void SetColour( const TRgb& aTextForeground,
const TRgb& aTextBackground,
const TRgb& aHighlightForeground,
const TRgb& aHighlightBackground );
private: // data
TRgb iTextForegroundColour;
TRgb iTextBackgroundColour;
TRgb iHighlightForegroundColour;
TRgb iHighlightBackgroundColour;
const CFont* iPersistentFont;
CFormattedCellListBoxData* iCellData;
TInt iScrollOffset;
};
class CDSListBox : public CAknDoubleNumberStyleListBox
{
public:
CDSListBox( const CFont* aFont,
CFormattedCellListBoxData* aFormattedCellListBoxData );
void SetScrollFrame();
void FindCellSize();
protected:
virtual void CreateItemDrawerL();
virtual CListBoxView* MakeViewClassInstanceL();
private:
const CFont* iFont;
CFormattedCellListBoxData* iFormattedCellListBoxData;
};
Source File
CDSListItemDrawer::CDSListItemDrawer( MTextListBoxModel* aTextListBoxModel,
const CFont* aFont,
CFormattedCellListBoxData* aFormatedCellData )
: CFormattedCellListBoxItemDrawer( aTextListBoxModel, aFont, aFormatedCellData ),
iPersistentFont( aFont )
{
}
void CDSListItemDrawer::DrawItemText( TInt aItemIndex,
const TRect &aItemTextRect,
TBool aItemIsCurrent,
TBool aViewIsEmphasized,
TBool aItemIsSelected) const
{
Gc()->SetBrushStyle( CGraphicsContext::ESolidBrush );
Gc()->SetBrushColor( KRgbWhite );
Gc()->Clear( aItemTextRect );
TPtrC itemText = iModel->ItemText( aItemIndex );
TInt textLength = itemText.Length();
TInt tabPosition1 = itemText.Locate( '\t' );
TInt tabPosition2 = itemText.Mid(tabPosition1+1).Locate( '\t' );
const CFont* font = Font( aItemIndex );
Gc()->SetPenStyle( CGraphicsContext::ESolidPen );
Gc()->SetBrushStyle( CGraphicsContext::ESolidBrush );
TRgb textColour;
TRgb bgColour;
if ( aItemIsCurrent )
{
textColour = iHighlightForegroundColour;
bgColour = iHighlightBackgroundColour;
}
else
{
textColour = iTextForegroundColour;
bgColour = iTextBackgroundColour;
}
Gc()->UseFont( iPersistentFont );
// Set the item's background.
Gc()->SetBrushStyle( CGraphicsContext::ESolidBrush );
Gc()->SetBrushColor( bgColour );
Gc()->SetPenColor( textColour );
TRect textRect( TPoint( aItemTextRect.iTl.iX, (aItemTextRect.iTl.iY-10) ),
aItemTextRect.iBr );
textRect.iBr.iY -= aItemTextRect.Height() / 2;
if ( !font )
{
font = CEikonEnv::Static()->LegendFont();
}
Gc()->UseFont(font);
TInt baseline = ( textRect.iBr.iY
- textRect.iTl.iY
- font->HeightInPixels() ) / 2 + font->AscentInPixels();
Gc()->DrawText( itemText.Mid( 0,tabPosition1 ),
textRect, baseline-20, CGraphicsContext::ELeft);
Gc()->DrawText( itemText.Mid( tabPosition1+1, tabPosition2 - tabPosition1 ),
textRect, baseline, CGraphicsContext::ELeft, 0);
font = CCoeEnv::Static()->NormalFont();
Gc()->UseFont(font);
textRect.Move( 0, aItemTextRect.Height() / 2 );
baseline = ( textRect.iBr.iY
- textRect.iTl.iY
- font->HeightInPixels() ) / 2 + font->AscentInPixels();
Gc()->DrawText( itemText.Mid( tabPosition2,textLength-tabPosition2 ),
textRect, baseline, CGraphicsContext::ELeft, 1);
}
void CDSListItemDrawer::SetColour( const TRgb& aTextForeground,
const TRgb& aTextBackground,
const TRgb& aHighlightForeground,
const TRgb& aHighlightBackground)
{
iTextForegroundColour = aTextForeground;
iTextBackgroundColour = aTextBackground;
iHighlightForegroundColour = aHighlightForeground;
iHighlightBackgroundColour = aHighlightBackground;
iBackColor = iTextBackgroundColour;
}
CDSListBox::CDSListBox( const CFont* aFont,
CFormattedCellListBoxData* aFormattedCellListBoxData )
{
iFont = aFont;
iFormattedCellListBoxData=aFormattedCellListBoxData;
}
void CDSListBox::CreateItemDrawerL()
{
iItemDrawer = new (ELeave) CDSListItemDrawer(
Model(),
iFont,
iFormattedCellListBoxData );
}
CListBoxView* CDSListBox::MakeViewClassInstanceL()
{
return new (ELeave) CListBoxView();
}
void CDSListBox::SetScrollFrame()
{
}
void CDSListBox::FindCellSize()
{
}
The calling function from a CCoeControl should contain:
SetExtentToWholeScreen(); // Drawing it to the whole screen
iTextForegroundColour = KRgbGreen;
iTextBackgroundColour = KRgbRed;
iHighlightForegroundColour = KRgbWhite;
iHighlightBackgroundColour = KRgbBlue;
iListItems = new (ELeave) CDesC16ArrayFlat( 2 );
const CFont *font;
_LIT( KTextFont, "LatinBold13" );
CFont* myFont;
CFormattedCellListBoxData* myFormattedCellListBoxData;
CGraphicsDevice* screenDevice = CEikonEnv::Static()->ScreenDevice();
TFontSpec textFontSpec( KTextFont, 200 );
screenDevice->GetNearestFontInTwips( myFont,textFontSpec );
myFormattedCellListBoxData = CFormattedCellListBoxData::NewL();
iListBox1 = new (ELeave) CDSListBox( myFont, myFormattedCellListBoxData );
iListBox1->ConstructL( this, 0 );
iListBox1->SetRect( TRect( 0, 0, 3000, 3000 ) );
CDSListItemDrawer* drawer = (CDSListItemDrawer*) iListBox1->View()->ItemDrawer();
drawer->SetColour( iTextForegroundColour,
iTextBackgroundColour,
iHighlightForegroundColour,
iHighlightBackgroundColour );
CColumnListBoxData* columnData=CColumnListBoxData::NewL();
columnData->SetControl( iListBox1 );
TInt columnSize;
columnData->ColumnWidthPixel( columnSize );
_LIT( KListItemFormat, "%d\t%S\t%S" );
_LIT( KName1, "Name11" );
_LIT( KContactNo,"123" );
_LIT( KName2,"Name22" );
_LIT( KContactNo2,"789" );
TBuf<40> item;
MDesCArray* itemList = iListBox1->Model()->ItemTextArray();
CDesCArray* itemArray = (CDesCArray*) itemList;
TBuf<30> NameBuf;
TBuf<30> ConBuf;
// add first item in the array
NameBuf.Copy( KName1 );
ConBuf.Copy( KContactNo );
TInt id = 1;
item.Format( KListItemFormat, id, &NameBuf, &ConBuf );
itemArray->AppendL( item );
// add second item in the array
NameBuf.Zero();
ConBuf.Zero();
NameBuf.Copy( KName2 );
ConBuf.Copy( KContactNo2 );
item.Format( KListItemFormat, id, &NameBuf, &ConBuf );
itemArray->AppendL( item );
NameBuf.Zero();
ConBuf.Zero();
iListBox1->SetRect( TRect( TPoint( 0,0 ),
TPoint( 20000, 20000 )) );
iListBox1->ActivateL();
iListBox1->HandleItemAdditionL();
DrawNow();
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