I need a QPushButton with two colors in the text. I found a solution with a html code in QTextDocument and it's working. But I need center align and the html code isn't working.
QTextDocument Text;
Text.setHtml("<p align=center><font>Button</font><br/><font color=yellow>1</font></p>");
QPixmap pixmap(Text.size().width(), Text.size().height());
pixmap.fill( Qt::transparent );
QPainter painter(&pixmap);
Text.drawContents(&painter, pixmap.rect());
QIcon ButtonIcon(pixmap);
ui->toolButton->setText("");
ui->toolButton->setIcon(ButtonIcon);
ui->toolButton->setIconSize(pixmap.rect().size());
And I get,
The same code HTML is working in a QLabel
ui->label->setText("<p align=center><font>Label</font><br/><font color=yellow>1</font></p>");
Any solution?
Thank very much.
As s workaround you can use a label or text document to print the text you want. You should paint it to a pixmap and use the pixmap on your button :
QPushButton *button = new QPushButton(this);
QTextDocument Text;
Text.setHtml("<h2><i>Hello</i> ""<font color=red>Qt!</font></h2>");
QPixmap pixmap(Text.size().width(), Text.size().height());
pixmap.fill( Qt::transparent );
QPainter painter( &pixmap );
Text.drawContents(&painter, pixmap.rect());
QIcon ButtonIcon(pixmap);
button->setIcon(ButtonIcon);
button->setIconSize(pixmap.rect().size());
You can also find a rich text push button implementation here.
An other option is to use QxtPushButton class from libqxt. QxtPushButton widget is an extended QPushButton with rotation and rich text support.
You can derive from QPushButton and draw text yourself via QPainter in paintEvent.
class Button : public QPushButton
{
Q_OBJECT
public:
Button(QWidget *parent = 0)
: QPushButton(parent)
{ }
void paintEvent(QPaintEvent *p)
{
QPushButton::paintEvent(p);
QPainter paint(this);
paint.drawText(QPoint(10,10),"Hello");
}
};
There is a bug report about this. When you use QTextDocument::drawContents, it tends to ignore the aligments. To make it work, set the text width using QTextDocument::setTextWidth.
QTextDocument doc;
doc.setHtml("<p align=center><font>Button</font><br/><font color=red>1</font></p>");
doc.setTextWidth(doc.size().width());
QPixmap pixmap(doc.size().width(), doc.size().height());
pixmap.fill( Qt::transparent );
QPainter painter(&pixmap);
doc.drawContents(&painter);
QPushButton button;
button.setIconSize(pixmap.size());
button.setIcon(pixmap);
button.show();
Related
I'm trying to draw on QLabel in Qt like this:
paintscene.h:
class PaintScene : public QWidget
{
Q_OBJECT
public:
PaintScene(QWidget* parent = NULL);
QVector<QLabel*> _layers;
QColor _color;
int _width;
void mousePressEvent(QMouseEvent* event);
private slots:
void updateWidth();
};
paintscene.cpp:
PaintScene::PaintScene(QWidget* parent) : QWidget(parent)
{
_width = 10;
_color = Qt::red;
QLabel* inital = new QLabel(this);
inital->setStyleSheet("QLabel { background-color : white; }");
_layers.push_back(inital);
QGridLayout* layout = new QGridLayout();
layout->addWidget(inital, 1, 1, 1, 1);
this->setLayout(layout);
}
void PaintScene::mousePressEvent(QMouseEvent *event)
{
QImage tmp = _layers.back()->pixmap()->toImage();
QPainter painter(&tmp);
QPen paintpen(_color);
paintpen.setWidth(_width);
painter.setPen(paintpen);
painter.drawPoint(event->x(), event->y());
_layers.back()->setPixmap(QPixmap::fromImage(tmp));
}
The list is needed because I want to implement the work with layers (QLabel - a separate layer).
However, I get an error, the program terminates. The error occurs on the line QImage tmp = _layers.back()->pixmap()->toImage();.
What makes this happen? How can this be fixed? Maybe for a layer to use something different, not QLabel?
#Jeremy Friesner is right about the reason for the error, not having a QPixmap this will be null, in my answer I will show a possible solution
void PaintScene::mousePressEvent(QMouseEvent *event)
{
QLabel *label = _layers.back();
const QPixmap *pix= label->pixmap();
QPixmap pixmap;
if(pix)
pixmap = *pix;
else{
pixmap = QPixmap(label->size());
pixmap.fill(Qt::transparent);
}
QPainter painter(&pixmap);
QPen paintpen(_color);
paintpen.setWidth(_width);
painter.setPen(paintpen);
painter.drawPoint(event->pos());
painter.end();
label->setPixmap(pixmap);
}
From the Qt docs for QLabel::pixmap():
This property holds the label's pixmap
If no pixmap has been set this will return 0.
... so when you do this:
QImage tmp = _layers.back()->pixmap()->toImage();
pixmap() is returning NULL (because the QLabel has never had any QPixmap set on it yet), and then you try to dereference that NULL pointer to call toImage() on it, hence the crash.
To avoid crashing, don't try to create a QImage from a NULL QPixmap pointer.
I suspect you wanted to be calling grab() instead of pixmap() -- grab() will create a QPixmap for you that contains the visual appearance of the QLabel. However, an even better approach would be to avoid messing about with QPixmaps at all; instead, make your own subclass of the QLabel class, and override its paintEvent(QPaintEvent *) method to first call up to QLabel::paintEvent(e) and then use a QPainter to draw the additional point afterwards. That will be easier to implement and also more efficient at runtime.
I am trying to grab the entire QTextEdit widget into QPainter using the following code:
QTextEdit *textEdit;
QPainter painter;
textEdit->render(&painter);
painter->restore();
This is the what I was able to grab.But, I would like to grab the hidden part of the widget as well into Qpainter. Any suggestions?
If you need to save content to image, you need to use QTextDocument::drawContents. Something like this:
QImage img;
QPainter p( &img );
auto doc = textEdit->document();
doc->drawContents( &p, textEdit->viewport()->size() );
I am trying to create a QPushButton in my project such that the text shows on top of the custom button image or icon.
I tried the below methods:
imagePath = path;
QPixmap pixmap(imagePath);
QIcon ButtonIcon(pixmap);
button->setIcon(ButtonIcon);
button->setIconSize(pixmap.rect().size());
button->setGeometry(0,0,height,width);
button->setStyleSheet(
"background-color: gray;"
"border: 1px solid black;"
"border-radius: "+QString::number(radius)+"px;"
"color: lightGray; "
"font-size: 25px;"
);
When I try to use the setText here, it shows the icon first and text on its right. I want the text to appear on top of the icon.
I also tried the below method I found online:
imagePath = path;
button->setGeometry(0,0,height,width);
button->setStyleSheet("background-image: url(:/images/images/2adjacentTracksButton.png));"
"background-position: center center");
This one is not accepting my url path, hence is not displaying the image I need on the button.
How can I solve this?
When it comes to manipulate button, you may want to do your own class, which will implement QAbstractButton. Something like this:
class MyButton : public QAbstractButton
{
Q_OBJECT
public:
static MyButton* createButton(QIcon icon, QWidget *parent);
~MyButton();
void setText(QString);
void setIcon(eIcon);
void setOrientation(Qt::Orientation);
protected :
MyButton(QWidget *parent);
// here, you can reimplement event like mousePressEvent or paintEvent
private :
QBoxLayout* m_ButtonLayout;
QLabel* m_IconLabel;
QIcon m_Icon;
QLabel* m_TextLabel;
}
In the .cpp :
MyButton::MyButton(QWidget *parent)
: QAbstractButton(parent)
{
m_ButtonLayout = new QBoxLayout(QBoxLayout::LeftToRight, this);
m_ButtonLayout->setAlignment(Qt::AlignCenter);
m_ButtonLayout->setContentsMargins(0, 0, 0, 0);
m_ButtonLayout->setSpacing(1);
m_IconLabel = new QLabel(this);
m_IconLabel->setAlignment(Qt::AlignCenter);
m_ButtonLayout->addWidget(m_IconLabel);
m_TextLabel = new QLabel(this);
m_TextLabel->setAlignment(Qt::AlignCenter);
m_ButtonLayout->addWidget(m_TextLabel);
//m_TextLabel->hide();
}
MyButton* MyButton::createButton(QIcon icon, QWidget *parent)
{
MyButton* pButton = new MyButton(parent);
pButton->setIcon(icon);
return pButton;
}
void MyButton::setText(QString text)
{
m_TextLabel->setVisible(!text.isEmpty());
m_TextLabel->setText(text);
QAbstractButton::setText(text);
}
void MyButton::setIcon(QIcon icon)
{
m_Icon = icon;
m_IconLabel->setVisible(true);
}
void MyButton::setOrientation(Qt::Orientation orientation)
{
if (orientation == Qt::Horizontal)
m_ButtonLayout->setDirection(QBoxLayout::LeftToRight);
else
m_ButtonLayout->setDirection(QBoxLayout::TopToBottom);
}
And now you can create your button with your icon by calling the static method:
MyButton* button = MyButton::createButton(myButtonIcon, this);
It is just a basic example I gave you, and I am not sure it will work (this is a thing I did some time ago) but you can give it a shot. Hope that helps !
I need to display a button on top of an image. Something similar to
The background is a QPixmap/QImage and the button is a QPushbutton. I need to be able to dynamically change the image - so I am not sure if a stylesheet would be suitable for the task. I tried this, but could not get it to work.
Any solutions?
Subclass QWidget and implement paintEent where you can paint your image at the background. Set and change background image by stylesheet also possible.
Add layout with button to this widget.
There are something like this:
class WidgetWithButton
: public QWidget
{
Q_OBJECT
QImage m_bgImage;
public:
WidgetWithButton(QWidget* aParent)
: QWidget(aParent)
{
QHBoxLayout* l = new QHBoxLayout(this);
QPushButton* myButton = new QPushButton(tr("Close"));
l->addWidget( myButton, 0, Qt::AlignCenter );
}
void setImage(const QImage& aImage)
{
m_image = aImage;
update();
}
protected:
virtual void paintEvent(QPaintEvent* aPainEvent)
{
if (m_image.isValid())
{
QPainter painter(this);
painter.drawImage(rect(), m_image);
}
else
QWidget::paintEvent(aPainEvent);
}
};
How do you convert/paint a QGraphicsTextItem into a QPixmap?
You can add it to a QGraphicsScene (if it's not already inside one) and then render() the scene to a QPixmap using a QPainter
QPixmap pix(100, 100);
QPainter paint(&pix);
scene.render(&paint);
Or, you can save yourself the trouble and just use QPainter::drawText() after changing the current font of the painter. it should provide the same capabilities.
Maybe something like this-
QPixmap pix(100, 100);
QPainter paint(&pix);
paint.drawText(0, 0, "Hello World");
The QGraphicsTextItem::document() function is the back door you're looking for:
// pItem is a QGraphicsTextItem *
QPixmap srcPixmap(pItem->boundingRect().size().toSize());
QPainter tmpPainter(&srcPixmap);
pItem->document()->drawContents(&tmpPainter);
tmpPainter.end()