I have already tried many solution that are provided on stackoverflow to make it transparent.
I want to make QRubberBand transparent and i am also facing problem regarding that green color which is due to mplayer.
#include "physician.h"
#include "ui_physician.h"
Physician::Physician(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::Physician)
{
ui->setupUi(this);
ui->sendROIButton->setStyleSheet(
"background-color: #d9d9d9;"
"border-radius: 10px;"
"color: Black; "
"font-size: 15px;"
);
}
Physician::~Physician()
{
delete ui;
}
void Physician::mouseMoveEvent(QMouseEvent *e)
{
rubberBand->hide();
bottomRight = e->pos();
QRect rect = QRect(topLeft, bottomRight).normalized();
rubberBand->setGeometry(rect);//Area Bounding
QToolTip::showText(e->globalPos(), QString("%1,%2")
.arg(rubberBand->size().width())
.arg(rubberBand->size().height()), this);
}
void Physician::mousePressEvent(QMouseEvent *e)
{
wWidth=ui->videoShowLabel->width();
wHeight = ui->videoShowLabel->height();
rubberBand->setGeometry(QRect(0, 0, 0, 0).normalized());
rubberBand->hide();
topLeft = e->pos();
}
void Physician::mouseReleaseEvent(QMouseEvent *e){
rubberBand->show();
}
void Physician::on_manualROIRadioButton_clicked()
{
rubberBand = new QRubberBand(QRubberBand::Rectangle, this);
}
void Physician::on_autoROIRadioButton_clicked()
{
QString winNuber= QString::number((int)(ui->videoShowLabel->winId()));
QStringList argsList ;
argsList << "-slave" << "-quiet" << "-wid" << winNuber << "zoom" << "-
vo" << "gl" << "C:/../../../Physician21/PhotoshopQML.mkv";
mplayer_proc = new QProcess;
mplayer_proc-
>start("C:/../../../PhysicianTest/mplayer/mplayer.exe",argsList);
}
Firstly, regarding "QRubberBand should work only on that QLabel". You need to make the QLabel the parent of the QRubberBand to achieve that.
Secondly, regarding transparency I assume you mean that the output from mplayer should be visible through the rectangle painted by the QRubberBand? I'm not sure you will be able to do that. Doing so would required the rubber band painting logic to act as a compositor but in order to do that it needs to know both the source and destination(mplayer) images. Since mplayer draws directly on the underlying native window Qt has know knowledge of the current destination image and so can not merge the source image with it. I think your best bet would be to find/generate a style that causes QRubberBand to draw the rectangle outline only -- not sure if that's possible. You could subclass it and do your own painting with something like...
class rubber_band: public QRubberBand {
using super = QRubberBand;
public:
template<typename... Types>
explicit rubber_band (const Types &... args)
: super(args...)
{}
protected:
virtual void paintEvent (QPaintEvent *event) override
{
QPainter painter(this);
painter.setPen(Qt::red);
painter.setBrush(Qt::NoBrush);
painter.drawRect(rect().adjusted(0, 0, -1, -1));
}
};
The above could still leave visual artifacts on the widget though.
Related
I have already used
setOpacity();
setAttribute(Qt:WA_TranseculentBackground:)
even i have tied all the available solution nothing has effect.
this is my code
void Physician::mouseMoveEvent(QMouseEvent *e)
{
rubberBand->hide();
bottomRight = e->pos();
QRect rect = QRect(topLeft, bottomRight);
rubberBand->setGeometry(rect);//Area Bounding
QToolTip::showText(e->globalPos(), QString("%1,%2")
.arg(rubberBand->size().width())
.arg(rubberBand->size().height()), this);
}
void Physician::mousePressEvent(QMouseEvent *e)
{
rubberBand->hide();
if(e->x()<ui->videoShowLabel->x()||e->y()<ui->videoShowLabel->y())
{
selectWithInLabel.critical(0,"Error", "Select within the LABEL !");
selectWithInLabel.setFixedSize(500, 200);
}
else{
topLeft = e->pos();
myPoint = ui->videoShowLabel->mapFromGlobal(this->mapToGlobal(e->pos()));
}
}
void Physician::mouseReleaseEvent(QMouseEvent *e){
rubberBand->setWindowOpacity(0.5);
rubberBand->show();
}
void Physician::on_manualROIRadioButton_clicked()
{
rubberBand = new RubberBand(RubberBand::Rectangle, this);
}
What should i do to make rubberBand semiTransparent
I assume you sub classed QRubberBand (RubberBand).
After calling the setWindowopacity the paint event is generated (http://doc.qt.io/qt-5/qwidget.html#windowOpacity-prop)
So redefine the paint event in RubberBand class.
Inside the paint event call "initStyleOption" (given below)
http://doc.qt.io/qt-5/qrubberband.html#initStyleOption
By calling "initStyleOption" you can set the rubber band parameters for drawing.
The real issue with making the QRubberband semi-transparent is that mplayer is painting on a window without Qt having any knowledge of it. Hence Qt itself cannot act as a compositor to generate the required effect.
One possibility would be to make the QRubberBand a top level window. That way the compositing is the responsibility of the underlying graphics system rather than Qt.
With that in mind try the following. Firstly a utility base class to manage the geometry...
class abstract_rubber_band {
public:
virtual QRect get_geometry () const
{
return(QRect(m_parent->mapFromGlobal(widget().geometry().topLeft()), widget().size()));
}
virtual void set_geometry (const QRect &rect)
{
widget().setGeometry(map_rect(rect));
}
protected:
explicit abstract_rubber_band (QWidget *parent)
: m_parent(parent)
{}
/*
* #param point Coords relative to effective parent.
*/
QPoint map_point (QPoint point) const
{
if (point.x() < 0)
point.rx() = 0;
else if (point.x() >= m_parent->width())
point.rx() = m_parent->width() - 1;
if (point.y() < 0)
point.ry() = 0;
else if (point.y() >= m_parent->height())
point.ry() = m_parent->height() - 1;
point = m_parent->mapToGlobal(point);
return(point);
}
QRect map_rect (QRect rect) const
{
return(QRect(map_point(rect.topLeft()), map_point(rect.bottomRight())));
}
private:
QWidget &widget ()
{
return(dynamic_cast<QWidget &>(*this));
}
const QWidget &widget () const
{
return(dynamic_cast<const QWidget &>(*this));
}
QWidget *m_parent;
};
Now use the above as a base of the required rubber band class...
class rubber_band: public abstract_rubber_band,
public QRubberBand {
using super = QRubberBand;
public:
/*
* #param parent Note that this isn't actually used as the
* parent widget but rather the widget to which
* this rubber_band should be confined.
*/
explicit rubber_band (QWidget *parent)
: abstract_rubber_band(parent)
, super(QRubberBand::Rectangle)
{
setAttribute(Qt::WA_TranslucentBackground, true);
}
protected:
virtual void paintEvent (QPaintEvent *event) override
{
QPainter painter(this);
painter.fillRect(rect(), QColor::fromRgbF(0.5, 0.5, 1.0, 0.25));
QPen pen(Qt::green);
pen.setWidth(5);
painter.setPen(pen);
painter.setBrush(Qt::NoBrush);
painter.drawRect(rect().adjusted(0, 0, -1, -1));
/*
* Display the current geometry in the top left corner.
*/
QRect geom(get_geometry());
painter.drawText(rect().adjusted(5, 5, 0, 0),
Qt::AlignLeft | Qt::AlignTop,
QString("%1x%2+%3+%4").arg(geom.width()).arg(geom.height()).arg(geom.left()).arg(geom.top()));
}
};
The above rubber_band class should almost be a drop in replacement for QRubberBand. The main difference is that rather than reading/writing its geometry with geometry/setGeometry you must use get_geometry/set_geometry -- those will perform the mapping to/from global coordinates.
In your particular case create the rubber_band with...
rubberBand = new rubber_band(ui->videoShowLabel);
I'm using QtCreator to build an interface application.
I'm just getting used to Qt and toying around trying to draw stuff on a QtGraphicsView.
Since I created my interface with the editor, I am retrieving my objects in the code like so (please tell me if this is wrong).
this->m_graphView = this->findChild<QGraphicsView *>("graphicsView");
this->m_graphScene = this->m_graphView->scene();
I have buttons on the interface and already created slots to react to the clicked event.
I'm just trying to draw something (anything) on the graphics view that is on my MainWindow (geometry : [(10,10), 320x240]).
I've been reading examples online and I can't make anything work.
My current code is as follows :
#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QDebug>
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
this->m_graphView = this->findChild<QGraphicsView *>("graphicsView");
this->m_graphScene = this->m_graphView->scene();
}
MainWindow::~MainWindow()
{
delete ui;
}
void MainWindow::on_btnDown_clicked()
{
qDebug() << "STUB : button DOWN";
m_graphScene->addLine(0, 0, 42, 42, QPen(QBrush(Qt::black),1));
m_graphView->show();
}
void MainWindow::on_btnLeft_clicked()
{
qDebug() << "STUB : button LEFT";
}
void MainWindow::on_btnUp_clicked()
{
qDebug() << "STUB : button UP";
}
void MainWindow::on_btnRight_clicked()
{
qDebug() << "STUB : button RIGHT";
}
void MainWindow::on_btnShoot_clicked()
{
qDebug() << "STUB : button SHOOT";
}
But annoyingly, it doesn't draw anything and I even get this error when the addLine method is called
QGraphicsScene::addItem: item has already been added to this scene
What's wrong in my code and/or my ways of doing things?
I just want to draw something but can't make it, thank you.
retrieving widget in form
you can get graphicsView pointer (and its scene) more easier.
"ui" member has the pointer to widgets arranged in .form file.
(If you please, see "ui_mainwindow.h" file)
// assign to pointer
QGraphicsView *view = ui->graphicsView;
view->...
// or directly (I like this)
ui->graphicsView->...
so, Mainwindow class don't need "m_graphicsView" member.
graphics view
QGraphicsView need to set scene.(It has no scene at first)
We have to create QGraphicsScene ourselves.
So Mainwindow class need "m_graphicsScene" member.
m_graphicsScene = new QGraphicsScene(this);
ui->graphicsView->setScene(m_graphicsScene);
drawing more easier
If you just want to draw something, you can override "paintEvent" method.
PaintEvent is QWidget's virtual method.
in .h file:
protected:
void paintEvent(QPaintEvent *event);
in .cpp file:
void MainWindow::paintEvent(QPaintEvent *event)
{
// unuse
Q_UNUSED(event);
// pass "this" pointer to painter
QPainter painter(this);
// setPen
// QPen can take "Qt::black" directly as first arg (without QBrush() constructor)
painter.setPen(QPen(Qt::black), 1);
// draw line
painter.drawLine(0, 0, 42, 42);
}
please enjoy Qt!
I am trying to get the positions of the graphicsitems in the scene.
But their QPointF value always remains (0,0).
I am painting when mouse-click event occurs. On debugging scene->items(), I get
(QGraphicsItem(this =0x22edff0, parent =0x0, pos =QPointF(0, 0) , z = 0 , flags = ( ) ) )
for each graphics item in scene but with different memory address.
This is my mainwindow.cpp code:
#include "mainwindow.h"
#include <QDebug>
MainWindow::MainWindow()
{
scene = new QGraphicsScene;
view = new QGraphicsView;
view->setScene(scene);
button = new QPushButton("Item");
QGridLayout *layout = new QGridLayout;
layout->addWidget(button);
layout->addWidget(view);
setLayout(layout);
connect(button, SIGNAL(clicked()), this, SLOT(createItem()));
}
void MainWindow::createItem()
{
myEntity = new Item;
scene->addItem(myEntity);
count_items();
}
void MainWindow::count_items()
{
qDebug() << scene->items().count();
qDebug() << scene->items();
}
MainWindow::~MainWindow()
{}
This is my item.cpp code:
#include "item.h"
Item::Item()
{
ClickFlag = true;
PaintFlag = false;
}
Item::~Item(){}
QRectF Item::boundingRect() const
{
// outer most edges
return QRectF(0,0,1450,1400);
}
void Item::mousePressEvent(QGraphicsSceneMouseEvent *event)
{
if(event->button()==Qt::LeftButton){
if(ClickFlag){
x = event->pos().x();
y = event->pos().y();
PaintFlag = true;
ClickFlag = false;
}
}
}
void Item::paint(QPainter *painter, const QStyleOptionGraphicsItem *option,
QWidget *widget)
{
if(PaintFlag){
QPen paintPen;
paintPen.setWidth(4);
pt.setX(x);
pt.setY(y);
painter->setPen(paintPen);
painter->drawPoint(x,y);
update();
}
}
I can't seem to find the position of these items correctly.
This task is supposed to be implemented in another way. For example:
Use QGraphicsScene::addEllipse to add small ellipse (which will look like a point) to the scene. Save the pointer to it in a class variable. The ellipse itself should be at the center, e.g. (-1, -1, 2, 2).
Reimplement QGraphicsScene::mousePressEvent, detect mouse clicks and call setPos for the ellipse item (or add new ellipse each time and immediately call setPos if you need multiple points).
Use QGraphicsItem::pos to get previously set positions.
Reimplementing QGraphicsItem::paint is usually an over-complication. Qt have plenty of item classes for all common needs. Just build your scene from geometric primitives, pixmaps, etc.
I'd appreciate help creating a top-level window in Qt with the following characteristics. The window must be:
Borderless, titleless and lie on top of all other windows on the desktop (easy)
Draggable by clicking and dragging anywhere inside it (this what I need help with)
Constrained to the top border of the desktop while dragging (relatively easy)
Basically, I'm trying to collapse our QT application to a top-level icon on the top border of the desktop.
You'll find the answer to the first part in: Making a borderless window with for Qt, and the answer to the second part in Select & moving Qwidget in the screen.
Combining the two, and adding the last part is straightforward.
Here's how you could do it:
#include <QtGui>
class W: public QWidget
{
Q_OBJECT
Set up a borderless widget with a few buttons to lock/unlock and quit:
public:
W(QWidget *parent=0)
: QWidget(parent, Qt::FramelessWindowHint), locked(false)
{
QPushButton *lock = new QPushButton("Lock");
QPushButton *unlock = new QPushButton("Unlock");
QPushButton *quit = new QPushButton("&Quit");
connect(lock, SIGNAL(clicked()), this, SLOT(lock()));
connect(unlock, SIGNAL(clicked()), this, SLOT(unlock()));
connect(quit, SIGNAL(clicked()),
QApplication::instance(), SLOT(quit()));
QHBoxLayout *l = new QHBoxLayout;
l->addWidget(lock);
l->addWidget(unlock);
l->addWidget(quit);
setLayout(l);
}
public slots:
void lock() {
locked = true;
move(x(), 0); // move window to the top of the screen
}
void unlock() { locked = false; }
Do the mouse handling:
protected:
void mousePressEvent(QMouseEvent *evt)
{
oldPos = evt->globalPos();
}
void mouseMoveEvent(QMouseEvent *evt)
{
const QPoint delta = evt->globalPos() - oldPos;
if (locked)
// if locked, ignore delta on y axis, stay at the top
move(x()+delta.x(), y());
else
move(x()+delta.x(), y()+delta.y());
oldPos = evt->globalPos();
}
private:
bool locked;
QPoint oldPos;
};
I need to create an alpha transparent widget, it's basically a navigation bar with a shadow and the widgets below need to be partially visible through the shadow. The widget loads a PNG then draws it on the paint event. The problem is that the shadow is all black and is not alpha-transparent.
This is the code I'm currently using:
NavigationBar::NavigationBar(QWidget *parent) : XQWidget(parent) {
backgroundPixmap_ = new QPixmap();
backgroundPixmap_->load(FilePaths::skinFile("NavigationBarBackground.png"), "png");
setAttribute(Qt::WA_NoBackground, true); // This is supposed to remove the background but there's still a (black) background
}
void NavigationBar::paintEvent(QPaintEvent* event) {
QWidget::paintEvent(event);
QPainter painter(this);
int x = 0;
while (x < width()) {
painter.drawPixmap(x, 0, backgroundPixmap_->width(), backgroundPixmap_->height(), *backgroundPixmap_);
x += backgroundPixmap_->width();
}
}
Does anybody know what I need to change to make sure the widget is really transparent?
You're doing too much work :-)
The setAttribute call is not necessary. By default, a widget will not draw anything on its background (assuming Qt >= 4.1). Calling QWidget::paintEvent is also unnecessary - you don't want it to do anything.
Rather than doing the pattern fill yourself, let Qt do it with a QBrush:
NavigationBar::NavigationBar(QWidget *parent) : XQWidget(parent) {
backgroundPixmap_ = new QPixmap();
backgroundPixmap_->load(FilePaths::skinFile("NavigationBarBackground.png"), "png");
// debug check here:
if (!backgroundPixmap_->hasAlphaChannel()) {
// won't work
}
}
void NavigationBar::paintEvent(QPaintEvent* event) {
QPainter painter(this);
painter.fillRect(0, 0, width(), height(), QBrush(*backgroundPixmap));
}
Adjust the height parameter if you don't want the pattern to repeat vertically.
Are you sure your PNG file is actually transparent? The following (which is essentially what you are doing) is working for me. If this fails on your machine, perhaps include what version of Qt you are using, and what platform.
#include <QtGui>
class TransparentWidget : public QWidget {
public:
TransparentWidget()
: QWidget(),
background_pixmap_(":/semi_transparent.png") {
setFixedSize(400, 100);
}
protected:
void paintEvent(QPaintEvent *) {
QPainter painter(this);
int x = 0;
while (x < width()) {
painter.drawPixmap(x, 0, background_pixmap_);
x += background_pixmap_.width();
}
}
private:
QPixmap background_pixmap_;
};
class ParentWidget : public QWidget {
public:
ParentWidget() : QWidget() {
QVBoxLayout *layout = new QVBoxLayout;
layout->addWidget(new TransparentWidget);
layout->addWidget(new QPushButton("Button"));
setLayout(layout);
setBackgroundRole(QPalette::Dark);
setAutoFillBackground(true);
}
};
int main(int argc, char **argv) {
QApplication app(argc, argv);
ParentWidget w;
w.show();
return app.exec();
}