Need Image rightside of QListwidget

[rajeshs]

Hi all ,

I am using QlistWidget icon along with text as iems, that icon is comming in left side,
I need another icon in rightside of the text? how can we draw icon within QListWidget?
please help me.

Thanks
Rajesh.S

[jpn]

• subclass QItemDelegate
• reimplement QItemDelegate::paint()
• calculate sufficient areas for decoration, check, etc.
• call each protected QItemDelegate::draw*() with calculated areas so that QItemDelegate::drawDecoration() ends up called twice; once with original icon and second time with icon being drawn on the right

[rajeshs]

Thank you for your reply , I am beginer to Qt, If you give some tips to how to use QItemDelegate, it will realy helpful to me.

Thanks
Rajesh.S

[jpn]

I was thinking of something like this. Keep in mind that the following snippet was written on the fly for demonstration purposes and is missing a whole lot of checks for valid values (QVariant::isValid()) etc.

class MyItemDelegate : public QItemDelegate
{
public:
	...
 
	void paint(QPainter* painter, const QStyleOptionViewItem& option, const QModelIndex& index) const
	{
		// calculate suitable area for text (excluding decorations)
		QString text = index.data(Qt::DisplayRole).toString();
		QRect displayRect = calcDisplayRect(text, option.fontMetrics);
 
		// calculate suitable area for decoration on the left
		QIcon icon1 = qvariant_cast<QIcon>(index.data(Qt::DecorationRole));
		QPixmap pixmap1 = icon1.pixmap(option.decorationSize);
		QRect decoration1Rect = calcDecorationRect(pixmap1, Qt::AlignLeft);
 
		// calculate suitable area for decoration on the right
		QIcon icon2 = qvariant_cast<QIcon>(index.data(Qt::UserRole));
		QPixmap pixmap2 = icon2.pixmap(option.decorationSize);
		QRect decoration2Rect = calcDecorationRect(pixmap2, Qt::AlignRight);
 
		// draw 'em
		drawBackground(painter, option, index);
		drawDecoration(painter, option, decoration1Rect, pixmap1);
		drawDecoration(painter, option, decoration2Rect, pixmap2);
		drawDisplay(painter, option, displayRect, text);
		drawFocus(painter, option, displayRect);
	}
};
 
// usage:
listWidget->setItemDelegate(new MyItemDelegate(listWidget));

class MyItemDelegate : public QItemDelegate
{
public:
	...

	void paint(QPainter* painter, const QStyleOptionViewItem& option, const QModelIndex& index) const
	{
		// calculate suitable area for text (excluding decorations)
		QString text = index.data(Qt::DisplayRole).toString();
		QRect displayRect = calcDisplayRect(text, option.fontMetrics);

		// calculate suitable area for decoration on the left
		QIcon icon1 = qvariant_cast<QIcon>(index.data(Qt::DecorationRole));
		QPixmap pixmap1 = icon1.pixmap(option.decorationSize);
		QRect decoration1Rect = calcDecorationRect(pixmap1, Qt::AlignLeft);

		// calculate suitable area for decoration on the right
		QIcon icon2 = qvariant_cast<QIcon>(index.data(Qt::UserRole));
		QPixmap pixmap2 = icon2.pixmap(option.decorationSize);
		QRect decoration2Rect = calcDecorationRect(pixmap2, Qt::AlignRight);

		// draw 'em
		drawBackground(painter, option, index);
		drawDecoration(painter, option, decoration1Rect, pixmap1);
		drawDecoration(painter, option, decoration2Rect, pixmap2);
		drawDisplay(painter, option, displayRect, text);
		drawFocus(painter, option, displayRect);
	}
};

// usage:
listWidget->setItemDelegate(new MyItemDelegate(listWidget));

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[rajeshs]

Thank you for your valuable answer,

I got idea about item delegate,and how to use this delegate,

How can we pass second image to our list using this delegate,

Thanks
Rajesh.S

[rajeshs]

Hello Sir,

I am using the following code to set image as list item,
using itemdelegate how can i pass second image

Please help me,


QString filen(":/resources/designer.png");
QListWidget listwidget;
QIcon icon(filen);

for(int i=0;i<l5.size();i++)
{
//populating into listwidget by text and image1
QListWidgetItem *item = new QListWidgetItem(icon,i,listwidget);
item->setTextAlignment(Qt::AlignHCenter);
item->setFont(fontSplitter3);
}

thanks
Rajesh.S

[rajeshs]

I am using QT 4.2 which header file i have to use for

calcDisplayRect() and calcDecorationRect()

Thanks
Rajesh.S

[jpn]

The example snippet above draws the ordinary icon (Qt::DecorationRole) on the left and a custom icon (Qt::UserRole) on the right:

listWidgetItem->setIcon(icon1); // same as setData(Qt::DecorationRole, QVariant::fromValue(icon1))
listWidgetItem->setData(Qt::UserRole, QVariant::fromValue(icon2));

listWidgetItem->setIcon(icon1); // same as setData(Qt::DecorationRole, QVariant::fromValue(icon1))
listWidgetItem->setData(Qt::UserRole, QVariant::fromValue(icon2));

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I am using QT 4.2 which header file i have to use for

calcDisplayRect() and calcDecorationRect()

These ones you are supposed to write by yourself. :)

[rajeshs]

Hello sir,

Thank you for your reply,Is it possible to use same itemdelegate for 2 different listwidgets?
Thaks
Rajesh.S

[rajeshs]

I am using itemdelegate for Qlistwidget and In item delegate,i am using painting to display icons and text as follows ,

if any other window pops up above this list , the painting in the list are faded away,

How can we prevent this,

My code in item delegate,

painter->drawPixmap(MyDelegate::x,MyDelegate::y,pixmap1) ;
painter->drawText(x+30,y+10,text);
if(text==" 11 Esig")
painter->drawPixmap(x+304,y,pixmap2);

Here x and y are coordinates,

please help me

[jpn]

Is it possible to use same itemdelegate for 2 different listwidgets?

Yes, it is. Use QAbstractItemView::setItemDelegate() as usual.

[rajeshs]

I used same item delegate for 2 listwidgets if i do that 2 listwidgets are comming empty.

and if any dialog pops up above to listwidget all items are faded away?

How can we handel this? Please help me!

Thaks
Rajesh.S

[jpn]

Geometry of painted item is passed in the style option. What are MyDelegate::x and MyDelegate::y? What's wrong with the approach I presented above?