Regarding the mirror effect required for text in QLabel

Pradeep Kumar

Hi,

I require the text in QLabel to be a mirror reflection format, so i went on some examples they provided for image in QLabel, can we have text in similar format, apart from image. Because i am using text in QLabel, can we have it, if yes can anyone guide me.

Thanks,

mrjj

Hi
What is to "a mirror reflection format" ?
Some sort of Text effect using real text instead of image ?

Pradeep Kumar

This post is deleted!

mrjj

@Pradeep-Kumar
Not seeing the image / link?

muratkarakus7

Wouldn't be easier to inherit from QLabel and override set text function. In that way, you can do custom processing for it.

Pradeep Kumar

This post is deleted!

Pradeep Kumar

sorry for the inconvenience

Here is the link

https://postimg.org/image/d727f14gb/

muratkarakus7

My solution would be overriding paintEvent of QLabel. You have to rotate text. It is a bit hard but you can start from qt source code to check default implementation of paintEvent and make a small change to rotate it. After that you can have another widget one with normal label big font, other with small font rotated text, put them into a layout and present to user. Or, if you can do all this in a label paintEvent.

http://stackoverflow.com/questions/26511409/qt-creator-rotate-a-qlabel-that-contains-text-90-degrees

Pradeep Kumar

I will give it a try guys. Will update.

muratkarakus7

Thanks!

I noted as well, I will try when I have time. In case I come up with a good looking widget, I will share with you guys.

mrjj

Hi
The hard part is most likely to get good looking reflection.
Some gradient and transparency will help but will take some playing around to look
nice. :)

? Offline

Hi! Maybe a bit over-engineered, but I'd use a custom QGraphicsEffect for this. The wiki article Text Shadows in QLabel shows how to apply it.

Pradeep Kumar

Guys with your help i have compiled the following code.

I have used 2 classes
Follow is the link where the code will be available.

By clicking QPushButton , i am showing QLabel.

classes i have used
LabelShadowEffect.h
LabelShadowEffect.cpp

http://codepaste.net/dke2fr
http://codepaste.net/jec1hm

and i have used LabelRotation Class where i have inherited from QLabel .
http://codepaste.net/gdvi11
http://codepaste.net/tqo8bn

Guys help me with the code where i require the alphabets to be reflected, but in the output, it is not.

Below is the link of the output

https://postimg.org/image/v13g6x943/

Guidance is required.

muratkarakus7

For the LabelRotation, I guess you should use righttoleft direction, then it will be how you want.

layoutDirection : Qt::LayoutDirection
This property holds the layout direction for this widget.
By default, this property is set to Qt::LeftToRight.

Pradeep Kumar

I used below line but still didnt work

painter.setLayoutDirection(Qt::RightToLeft);

can u share the piece of code or edit in the code which i provided in the link. I will also try to make it work.

? Offline

Here is an example using QGraphicsEffect. The result looks like this:

mainwindow.cpp

//...
#include "myeffect.h"

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    MyEffect *effect = new MyEffect(this);
    ui->label->setGraphicsEffect(effect);
}
//...

myeffect.h

#ifndef MYEFFECT_H
#define MYEFFECT_H

#include <QGraphicsEffect>

class MyEffect : public QGraphicsEffect
{
    Q_OBJECT
public:
    MyEffect(QObject *parent = Q_NULLPTR);
    virtual QRectF boundingRectFor(const QRectF &sourceRect) const override;
    virtual void draw(QPainter *painter) override;
};

#endif // MYEFFECT_H

myeffect.cpp

#include "myeffect.h"

#include <QPainter>
#include <QPixmap>
#include <QPoint>
#include <QSize>

MyEffect::MyEffect(QObject *parent)
    : QGraphicsEffect(parent)
{
}

QRectF MyEffect::boundingRectFor(const QRectF &sourceRect) const
{
    return sourceRect.adjusted(0, 0, 0, sourceRect.height());
}

void MyEffect::draw(QPainter *painter)
{
    painter->save();
    QPoint offset;
    const QPixmap pixmap = sourcePixmap(Qt::LogicalCoordinates, &offset);
    painter->drawPixmap(offset, pixmap);

    QImage img = pixmap.toImage();
    const QSize s = img.size();
    const qreal fac = 255.0 / s.height();
    const qreal brightness = 0.9;
    for (int i=0; i<s.width(); ++i) {
        for (int j=0; j<s.height(); ++j) {
            QRgb argb = img.pixel(i,j);
            int grayValue = (255-(fac*j))*brightness;
            grayValue = grayValue < 0 ? 0 : grayValue;
            grayValue = grayValue > 255 ? 255 : grayValue;
            QColor newColor(grayValue, grayValue, grayValue, qAlpha(argb));
            img.setPixelColor(i,j,newColor);
        }
    }
    img = img.mirrored();
    painter->drawImage(0,0, img);
    painter->restore();
}

Hope it helps!

Pradeep Kumar

Thanks man
I got the output , here is the link of the output which got.

https://postimg.org/image/qtwp1ywst/

Thanks,

Pradeep Kumar

Thanks guys @muratkarakus7 @mrjj @Wieland for your support, marking as solved, which will be useful.

Thanks.