How to make size of button in the LineEdit smaller? - qt

I made the X button in the LineEdit, when i click on this button, the LineEdit is clear. But with my method, the X button looks a little big and not beautiful, I need to make it smaller. How I can do it?
myLineEdit = new LineEdit;
myLineEdit->setFixedHeight( 25 );
m_clear = m_lineEdit->addAction( QIcon( ":/clearButton" ), QLineEdit::TrailingPosition );
the size of clearButton.png is 12x12 px, so in this case it is enlarged and looks not beautiful like this.

For this solution it is assumed that in the original image the relationship between the foreground size and the background is 1: 1 (this is normal in the icons), so the solution is to increase that relationship, for this we create a new image
QPixmap in(":/clearButton");
QPixmap out(in.size()*10/7);
QRect r= in.rect();
r.moveCenter(out.rect().center());
out.fill(Qt::transparent);
QPainter painter(&out);
painter.drawPixmap(r , in);
painter.end();
QLineEdit *m_lineEdit = new QLineEdit;
m_lineEdit->setFixedHeight(25);
m_lineEdit->addAction(QIcon(out), QLineEdit::TrailingPosition);
Before:
After:

Related

QPushButton icon maximize on resize event

I have a question about resizing an icon on a QPushButton. Target system is Qt 4.8.6 on Linux. I am using QPushButton to create buttons with icons only, no text. I would like to have the icon as large as possible centered on the button including some margin.
I do not want the button size to adapt to the image size, I want the image size to adapt to the button size, while the button size adapts automaticly to the GUI size through QGridLayout or manually resizing.
When simply creating the button, the icon is only loaded small within the middle:
const QString fileName = "Bitmaps/btn.png";
if( !QFile( fileName ).exists() )
{
qDebug() << "File not found: " << fileName;
}
const QPixmap pixmap = QPixmap( fileName );
m_btn = new QPushButton( QIcon( pixmap ), "", this );
When resizing through manual setting, the icon does not scale:
m_btn->setGeometry( QRect( 100, 100, 50, 50 ) );
To get the icon size rescaled I need to manually call setIconSize(). I can call this within the resize event of the instanciating widget.
But handling the margin still has to be calculated manually.
m_btn->setIconSize( QSize( ( m_btn->size().width() - 12 ),
( m_btn->size().height() - 12 ) ) );
But, as I get from the Qt Documentation there is a Stylesheet based layout thing called "The Box Model" which is applied to QPushButton as well.
http://doc.qt.io/qt-4.8/stylesheet-customizing.html#box-model
So my question is, how do I configure the push button icon to fill the "content" area (marked as grey in the above document).
Possibly how do I configure it, that the icon resizes automaticly?
Your help is appreciated :-)

QT - Increase Richtext size on Button click

How do i increase the size of a Rich Text on the click of a button ?
I have a QTextEdit box with Rich text pasted in it.On the click of a + [ui button] i need to increase the font size of all the text inside it. Any idea on how to do that ?
Solution
This is what you should do inside the slot :
//-------------------------desired format-------------------------------
qreal pointSize = 40; // 40 for example, you can parameterize it
QTextCharFormat format;
format.setFontPointSize(pointSize);
//----------------------------------------------------------------------
ui->textEdit->selectAll();
// ^^^^^^^^^^^ You ask for all text in the textedit
// But remember partially change with mouse selection is also doable
ui->textEdit->mergeCurrentCharFormat(format);
(P.S. ui->textEdit is a pointer to QTextEdit)
The key point is to create an instance of QTextCharFormat to set the "partial" information of the font (Ex: size information only) and use QTextEdit::mergeCurrentCharFormat to merge the original format with the new format.
For example:
After merging by the operations above, the color, font...etc except size will be retained:
You can use the QTestEdit::setCurrentFont() function. For example:
QTextEdit te;
QFont f = te.currentFont();
int oldPointSize = f.pointSize();
int newPointSize = oldPointSize + 10;
f.setPointSize(newPointSize);
te.setCurrentFont(f);
te.setText("Test");
te.show();

QLinearGradient doesn't work properly with QBrush

I want to draw 1 digit on the screen by the graphic framework classes. I want the fill approach of '1' to be something like
(source: qt-project.org)
but the brush of my drawn '1' is just like a yellow SolidBrush by the below code (an ugly bold yellow '1'). Can you help me what's wrong with it?
QGraphicsSimpleTextItem digit_1 = new QGraphicsSimpleTextItem;
digit_1->setText(QString::number(1));
digit_1->setPen(QPen(QColor("black")));
QLinearGradient gradient(digit_1->boundingRect().topLeft(),
digit_1->boundingRect().bottomRight());
gradient.setColorAt(0, Qt::white);
gradient.setColorAt(1, Qt::yellow); // yellow is for example
QBrush brush(gradient);
brush.setStyle(Qt::BrushStyle::LinearGradientPattern);
digit_1->setBrush(brush);
digit_1->setFont(QFont("courier", 35, QFont::Black));
Thanks in advanced.
Your issue most likely comes from the fact that you're basing your gradient's "area" on the bounding rect of your item before you set the font size to something much larger than the default.
The bounding rect you're getting is thus much smaller than your actual bounding rect. Since the default spread method is padding, you're seeing most likely just one color (or not enough of the gradient for it to be actually visible).
So move your setFont call to the top, before you create the gradient. You can drop the setStyle on your brush, that's determined automatically from the gradient. (In fact, you can drop that brush entirely and use the gradient in setBrush.)
With the way you set up the gradient, you'll get a "diagonal" gradient. If you want it from top to bottom, use the top left and bottom left points instead.
Demo
#include <QtGui>
class W: public QGraphicsView
{
Q_OBJECT
public:
W(QWidget *parent = 0)
: QGraphicsView(parent)
{
QGraphicsSimpleTextItem *item = new QGraphicsSimpleTextItem;
item->setText("Stack Overflow");
item->setPen(QPen(Qt::red));
item->setFont(QFont("courier", 60, QFont::Bold));
QLinearGradient lgrad(item->boundingRect().topLeft(),
item->boundingRect().bottomLeft());
lgrad.setColorAt(0.0, Qt::red);
lgrad.setColorAt(1.0, Qt::yellow);
item->setBrush(lgrad);
QGraphicsScene *scene = new QGraphicsScene;
scene->setBackgroundBrush(QBrush(Qt::black));
scene->addItem(item);
setScene(scene);
}
};

How to set the size of a QGraphicsView?

I'd like to have a fixed size QGraphicsView, which I want to add to a layout together with some other widgets. However, the QGraphicsView simply ignores resize(), here is the relevant code:
QGraphicsScene* scene = new QGraphicsScene;
QGraphicsView* view = new QGraphicsView(scene);
view->setBackgroundBrush(QBrush(Qt::black, Qt::SolidPattern));
view->resize(1000, 600);
QVBoxLayout* layout = new QVBoxLayout;
layout->setMargin(0);
layout->addWidget(view);
setLayout(layout);
If I use setFixedSize() instead of resize(), the size is actually being set correctly. However, it seems that the window size is not updated, the window is not centered properly.
How am I supposed to set a fixed size for a QGraphicsView?
I know this is a very old question, but in case anyone else stumbles into it: you can set both minimumSize and maximumSize to the desired target size, and it should work regardless of what layout the QGraphicsView is in.
If I understood you right you want to have QGraphicsView centred inside the window and having fixed size. You need rather then VBoxLayout you should use QGridLayout with spacers, so your form should look like:
<Empty> <VSpacer> <Empty>
<HSpacer> <GraphicsView> <HSpacer>
<Empty> <VSpacer> <Empty>

Moving a QPixmap to the corner of a QGraphicsScene

I have a QGraphicsView and a QGraphicsScene connected like this:
graphicsScene->setSceneRect(this->graphicsView->rect());
graphicsView->setScene(this->Scene);
Then I load an image and add it to the scene:
QPixmap pixmap;
pixmap.load(fileName);
pixmap = pixmap.scaled(this->graphicsView->size());
QGraphicsPixmapItem* item = this->Scene->addPixmap(pixmap);
Now, as described in the documentation, the image corner is at (0,0), which is not the corner of the graphicsScene. I know I can position the resulting pixmap by doing:
item->setPos(this->Scene->sceneRect().x(), this->Scene->sceneRect().y());
However, I can't seem to make sense of the coordinates of the rect's of the scene or the view. Can anyone explain how I would move the pixmap to the corner of the scene/view?
Thanks,
David
EDIT: Here is the full form constructor. The QGraphicsView was created in Qt Designer and is inside of a GridLayout:
Form::Form(QWidget *parent)
: QWidget(parent)
{
setupUi(this);
QGraphicsScene* scene = new QGraphicsScene;
scene->setSceneRect(this->graphicsView->rect());
this->graphicsView->setScene(scene);
QPixmap pixmap;
pixmap.load("image.png");
pixmap = pixmap.scaled(this->graphicsView->size());
scene->addPixmap(pixmap);
}
I also tried this:
QGraphicsScene* scene = new QGraphicsScene;
this->graphicsView->setScene(scene);
QPixmap pixmap;
pixmap.load("/home/doriad/glasses.jpg");
QGraphicsPixmapItem * item = scene->addPixmap(pixmap);
this->graphicsView->fitInView (item);
but the image appears tiny, rather than filling up the view like I would expect. Can anyone explain this?
The full project and image are available here: daviddoria.com/Uploads/qt/QPixmapPosition
Don't worry about scaling the pixmap yourself or even translating it, let the view do it for you.
Use graphicsView->fitInView(pixmap); but you should read the documentation for :
Qt's Graphics View Framework
void QGraphicsView::setSceneRect (QRectF )
void QGraphicsView::translate ( qreal dx, qreal dy )
void QGraphicsView::fitInView ( const QGraphicsItem * item, ... )
The way that QGraphicsScene and QGraphicsView interact is that you can have a single scene with at least one or more views.
A good example I like to think of is a zoomed in view of part of a map with a mini view of the entire map in the corner. There are two views, one of part of the map and one of the entire map, with one scene, the map itself.
So you put items in your scene and all the items in the scene are drawn relative in size to each other. The "scene rect" of your view, by default, scales to fit the items in the view until one unit in the scene is one pixel in the view or until it needs to zoom out to fit all the items in your scene.
If you call fitInView(someItem) it should scale your view of the scene so that the item specified fills it up and translates the view so that it is centered. If you need to translate or scale it more use the translate or scale functions in QGraphicsView.
When you are jumping between coordinate systems of your scene and view with your QRect's or QPoint's, use the helper functions: mapToScene and mapFromScene from QGraphicsView.
Try this:
QGraphicsScene* scene = new QGraphicsScene;
scene->setSceneRect(graphicsView->sceneRect());
QPixmap pixmap;
pixmap.load("/home/doriad/glasses.jpg");
pixmap=pixmap.scaledToWidth(this->graphicsView->width());
QGraphicsPixmapItem * item = scene->addPixmap(pixmap);
graphicsView->setScene(scene);
By default, the pixmap will be at (0,0) in the scene, and the scene will be at (0,0) in the view. QWidgets are sized by pixels. If you had a QGraphicsView the size of the screen and the resolution is 1440 x 900, you can position objects in that view from (0,0) or the top left corner of the screen, to (1440,900) the bottom right corner of the screen. Most QGraphicsItems are placed with reference to their top left corner. So placing a pixmap at (0,0) aligns the top left corner of the pixmap with the top left corner of the scene it's placed in. If your pixmap 'hangs off the bottom' of your view, try using:
pixmap=pixmap.scaledToHeight(this->graphicsView->height());
If you use the function:
this->graphicsView->fitInView (item);
The graphicsView will only scroll to the point where your item fits in the view.
I downloaded David's code and ran it two ways. Click the links to see the results.
1) with pixmap=pixmap.scaledToHeight(this->graphicsView->height());
2) with pixmap=pixmap.scaledToHeight(200);
I don't know enough to explain why this is happening, but I thought it would be a useful data point.
It turns out the problem was that the GraphicsView was in a layout. In my example, the resizing of the image was done in the Form constructor. Apparently this is before the layout takes its shape? I moved the code to a pushButton and when I click it the image is sized how I would expect.
I got the image to stay sized to the GraphicsView in the Layout by subclassing QGraphicsView and reimplementing :
class CustomGraphicsView: public QGraphicsView
{
Q_OBJECT
{
void resizeEvent ( QResizeEvent * event )
{
emit resized();
}
signals:
void resized();
}
Then I connect this resized() signal to a slot that simply calls this->View->fitInView (this->ImageToTraceItem);
David

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