I have a table with 3 columns. the second column content is smaller than the other two. so when I initialize the parent object(QMainWindow) I resize columns like this:
QSize tblSize = ui.tblUsers->size();
ui.tblUsers->setColumnWidth(0, 3 * tblSize .width() / 8);
ui.tblUsers->setColumnWidth(1, 2 * tblSize .width() / 8);
ui.tblUsers->setColumnWidth(2, 3 * tblSize .width() / 8);
everything is nice and good until the number of rows increases and a vertical scroll bar is added to the table. this scroll bar will take space and so the sum of width given to columns will exceed tables width( old width - scroll bar width). and because of that a horizontal scroll bar is added too which makes things very ugly.
so is there anyway to fix this problem? for example is there anyway to check to see if there will be a vertical scroll bar and then resize columns like this:
QSize tblSize = ui.tblUsers->size();
ui.tblUsers->setColumnWidth(0, 3 * (tblSize .width()-scrollBarSize) / 8);
ui.tblUsers->setColumnWidth(1, 2 * (tblSize .width()-scrollBarSize) / 8);
ui.tblUsers->setColumnWidth(2, 3 * (tblSize .width()-scrollBarSize) / 8);
You can installEventFilter() and intercept scroll bar QShowEvent, then resize columns on it:
int sz = tblSize.width();
if (ui.tblUsers->verticalScrollBar()->isVisible())
sz -= ui.tblUsers->verticalScrollBar()->width();
ui.tblUsers->setColumnWidth(0, 3 * sz/8);
ui.tblUsers->setColumnWidth(1, 2 * sz/8);
ui.tblUsers->setColumnWidth(2, 3 * sz/8);
Also consider ui.tblUsers->setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOn).
Update 2
ui.tblUsers->installEventFilter(this);
bool MainWindow::eventFilter(QObject *obj, QEvent *event) {
if(obj==ui.tblUsers) {
if (event->type() == QEvent::Show || event->type() == QEvent::Hide) {
recalculateColumnSizes(); //create such function
return true;
}
}
return __super::eventFilter(obj, event);
}
Related
I have some horizontal QSliders in my Qt application with 4-5 ticks marks. How can I add QLabels above the slider ticks to reflect the value at each of the ticks?
I suspect the best way to do this is to create a subclass of QSlider and override the paintEvent() method like this answer describes. But how would I add QLabels based on the position of the ticks?
For clarification:
I am looking for Text labels at each tick, ie if I have a slider that goes from 0 - 100 with 4 ticks, the ticks would have "0", "25", "50", and "100" above them, respectively. Your solution is still helpful, I believe I should be able to rework it using this->geometry to get the coordinates and dividing by # of ticks (which I believe I can calculate with (max - min/tick interval)
There is an implementation in PySide that works properly. It displays the rounded value of each tick, you can replace it with whatever text you need by updating the QPainter::drawText callback.
Long time ago, I did port that code to C++. This is the interesting part:
void MySlider::painEvent(...) {
QSlider::paintEvent(self, event)
auto round_value = std::floor(value());
auto painter = new QPainter(this);
painter->setPen(QPen(Qt::white));
auto font_metrics = QFontMetrics(this->font());
auto font_width = font_metrics.boundingRect(QString::number(round_value)).width();
auto font_height = font_metrics.boundingRect(QString::number(round_value)).height();
auto rect = w.geometry();
if (this->orientation() == Qt::Horizontal) {
auto horizontal_x_pos = rect.width() - font_width - 5;
auto horizontal_y_pos = rect.height() * 0.75;
painter->drawText(QPoint(horizontal_x_pos, horizontal_y_pos),
QString::number(round_value));
} else if (this->orientation() == Qt::Vertical) {
auto vertical_x_pos = rect.width() - font_width - 5;
auto vertical_y_pos = rect.height() * 0.75;
painter->drawText(QPoint(rect.width() / 2.0 - font_width / 2.0, rect.height() - 5),
QString::number(round_value));
} else {
return;
}
painter->drawRect(rect)
}
I am using QFormLayout with QLabels in the left column and various widgets in the right column. On the right, there are either labels, check boxes, combos or line edits. Unfortunately each of there controls has different natural height. But I would like to have each row in the form layout to have equal heights determined by the biggest one (I know in which row it is). Is there any simple way to achieve this? I cannot find anything like QFormLayout::setRowHeight().
One solution, just assign equal size to all widgets at runtime using the following function:
void setEqualRowHeight(QFormLayout *formLayout, int height)
{
QWidget *w;
for(int i = 0; i < formLayout->rowCount(); i++) {
QLayoutItem *item = formLayout->itemAt(i, QFormLayout::FieldRole);
if (item && (w = item->widget())) {
w->setFixedHeight(height);
}
}
}
I have a QGraphicsTextItem parented to a QGraphicsItem. I want the QGraphicsTextItem to always reside directly above the QGraphicsItem, but I also want the text to remain the same size when the scale factor goes below 1, i.e. the text remains the size it is at a scale factor of 1 even when the parent graphics item is scaled smaller. I have found that setting the QGraphicsItem::ItemIgnoresTransformations flag to true when the scale factor is below 1 does the trick for retaining the size.
But I can’t seem to find a way to get the position of the text to always remain above the QGraphicsItem. Is there a way to do this? I tried using deviceTransform () function, but the text still moved off of the QGraphicsItem as I scrolled out. What was worse is that some of the text items started “jiggling”, i.e. they started continuously changing their position ever so slightly, so that it looked like they were shaking. If this is the function I need to use, I guess I don’t know how to use it properly.
In the constructor of my QGraphicsItem I’ve added a QGraphicsTextItem:
fTextItem = new QGraphicsTextItem(getName(), this);
fTextItem->setFlag(QGraphicsItem::ItemIgnoresTransformations);
Here is code snippet from paint function of QGraphicsItem
qreal lod = painter->worldTransform().m22();
if(lod <= 1.0) {
fTextItem-setFlag(QGraphicsItem::ItemIgnoresTransformations);
fTextItem->setPos(fTextItem->deviceTransform(view-viewportTransform()).inverted().map(view->mapFromScene(mapToScene(0,0))));
} else {
fTextItem->setFlag(QGraphicsItem::ItemIgnoresTransformations, false);
fTextItem->setPos(0, 0);
}
My suggestion is to subclass QGraphicsSimpleTextItem in this manner:
class TextItem
: public QGraphicsSimpleTextItem
{
public:
TextItem(const QString &text)
: QGraphicsSimpleTextItem(text)
{
}
void paint(QPainter *painter,
const QStyleOptionGraphicsItem *option, QWidget *widget)
{
painter->translate(boundingRect().topLeft());
QGraphicsSimpleTextItem::paint(painter, option, widget);
painter->translate(-boundingRect().topLeft());
}
QRectF boundingRect() const
{
QRectF b = QGraphicsSimpleTextItem::boundingRect();
return QRectF(b.x()-b.width()/2.0, b.y()-b.height()/2.0,
b.width(), b.height());
}
};
QGraphicsSimpleTextItem *mText = new TextItem("Item");
scene()->addItem(mText);
mText->setFlag(QGraphicsItem::ItemIgnoresTransformations, true);
mText->setPos(itemToFollow->pos());
Disclaimer: this may be overkill for what you are trying to do. We had some additional restrictions in our project that made this solution the easiest for us.
We had to do something similar in a project, and it ended up being easiest for us to not use ItemIgnoresTransformations and instead roll our own transform. Here is the main function we use to create a translation-only (no scaling) transform for drawing an item at a specific location. You might be able to modify it for your usage.
static QTransform GenerateTranslationOnlyTransform(
const QTransform &original_transform,
const QPointF &target_point) {
// To draw the unscaled icons, we desire a transform with scaling factors
// of 1 and shearing factors of 0 and the appropriate translation such that
// our icon center ends up at the same point. According to the
// documentation, QTransform transforms a point in the plane to another
// point using the following formulas:
// x' = m11*x + m21*y + dx
// y' = m22*y + m12*x + dy
//
// For our new transform, m11 and m22 (scaling) are 1, and m21 and m12
// (shearing) are 0. Since we want x' and y' to be the same, we have the
// following equations:
// m11*x + m21*y + dx = x + dx[new]
// m22*y + m12*x + dy = y + dy[new]
//
// Thus,
// dx[new] = m11*x - x + m21*y + dx
// dy[new] = m22*y - y + m12*x + dy
qreal dx = original_transform.m11() * target_point.x()
- target_point.x()
+ original_transform.m21() * target_point.y()
+ original_transform.m31();
qreal dy = original_transform.m22() * target_point.y()
- target_point.y()
+ original_transform.m12() * target_point.x()
+ original_transform.m32();
return QTransform::fromTranslate(dx, dy);
}
To use, take the QPainter transform that is passed to the paint method and do something like:
painter->save();
painter->setTransform(GenerateTranslationOnlyTransform(painter->transform(),
some_point));
// Draw your item.
painter->restore();
I've found another solution, which does not involve messing with any transformations or by hand scaling/positioning. There is a hint in QGraphicsItem::ItemIgnoresTransformations flag description:
QGraphicsItem::ItemIgnoresTransformations
The item ignores inherited transformations (i.e., its position is
still anchored to its parent, but the parent or view rotation, zoom or
shear transformations are ignored). [...]
And that's the key! We need two items: a parent that will keep the relative position (without any flags set) and a child item that will do the drawing at parent's (0,0) point (with QGraphicsItem::ItemIgnoresTransformations flag set). Simple as that!
I've encapsulated this functionality into a single class - here is some code:
#include <QGraphicsItem>
#include <QPainter>
class SampleShape : public QGraphicsItem
{
private:
/* This class implements shape drawing */
class SampleShapeImpl : public QGraphicsItem
{
public:
SampleShapeImpl (qreal len, QGraphicsItem *parent = nullptr)
: QGraphicsItem(parent), m_len(len)
{
/* ignore transformations (!) */
setFlag(QGraphicsItem::ItemIgnoresTransformations);
}
QRectF boundingRect (void) const override
{
/* sample bounding rectangle */
return QRectF(-m_len, -m_len, m_len*2, m_len*2);
}
void paint (QPainter *painter, const QStyleOptionGraphicsItem *, QWidget *) override
{
/* draw a shape, (0,0) is an anchor */
painter->drawLine(0, -m_len, 0, m_len);
painter->drawLine(-m_len, 0, m_len, 0);
// ...
}
private:
qreal m_len; // sample shape parameter
};
public:
/* This is actually almost an empty class, you only need to set
* a position and pass any parameters to a SampleShapeImpl class.
*/
SampleShape (qreal x, qreal y, qreal len, QGraphicsItem *parent = nullptr)
: QGraphicsItem(parent), m_impl(len, this) // <-- IMPORTANT!!!
{
/* set position at (x, y), view transformations will apply */
setPos(x, y);
}
QRectF boundingRect (void) const override
{
return QRectF(); // it's just a point, no size
}
void paint (QPainter *, const QStyleOptionGraphicsItem *, QWidget *) override
{
// empty, drawing is done in SampleShapeImpl
}
private:
SampleShapeImpl m_impl;
};
Great answer by Dave Mateer! I had the problem that I wanted to define a different scale factor at different zoom levels. This is how I did it:
void MyGraphicsItem::paint(QPainter * painter, const QStyleOptionGraphicsItem* option, QWidget* widget)
{
//save painter for later operations
painter->save();
QTransform originalTransform = painter->transform();
QPointF originalCenter = rect().center();
qreal dx = originalTransform.m11() * originalCenter.x() + originalTransform.m21() * originalCenter.y() + originalTransform.m31();
qreal dy = originalTransform.m22() * originalCenter.y() + originalTransform.m12() * originalCenter.x() + originalTransform.m32();
//normally our target scale factor is 1, meaning the item has keeps its size, regardless of zoom
//we adjust the scale factor though when the item is smaller than one pixel in comparison to the background image
qreal factor = 1.0;
//check if scale factor if bigger that the item size, and thus it occupies less that a pixel in comparision to the background image
if (rect().width() < originalTransform.m11()) {
//calculate adjusted scale factor
factor = originalTransform.m11() / rect().width();
}
//adjust position according to scale factor
dx -= factor * originalCenter.x();
dy -= factor * originalCenter.y();
//set the new transform for painting
painter->setTransform(QTransform::fromScale(factor, factor) * QTransform::fromTranslate(dx, dy));
//now paint...
QGraphicsXYZItem::paint(painter, option, widget);
//restore original painter
painter->restore();
}
You do need to adjust the bounding rectangle too in that case:
QRectF MyGraphicsItem::boundingRect() const
{
QRectF rect = QGraphicsEllipseItem::boundingRect();
//this is a bit hackish, let me know if you know another way...
if (scene() != NULL && scene()->views().at(0) != NULL)
{
//get viewport transform
QTransform itemTransform = scene()->views().at(0)->transform();
QPointF originalCenter = rect.center();
//calculate back-projected original size of item
qreal realSizeX = rect.width() / itemTransform.m11();
qreal realSizeY = rect.height() / itemTransform.m11();
//check if scale factor is bigger that the item size, and thus it occupies less that a pixel in comparison
//to the background image and adjust size back to equivalent of 1 pixel
realSizeX = realSizeX < 1.0 ? 1.0 : realSizeX;
realSizeY = realSizeY < 1.0 ? 1.0 : realSizeY;
//set adjusted position and size according to scale factor
rect = QRectF(rect.center().x() - realSizeX / 2.0, rect.center().y() - realSizeY / 2.0, realSizeX, realSizeY);
}
return rect;
}
With this solution the item work very well in my case.
Adding to Dave Mateer's answer, I think it'd be helpful to add that in some scenario, you should also maintain proper bounding rectangle (as well as shape) of the object. For me, I need to modify boundingRect() a little too for proper object selection behavior. Remember that the bounding rect of the object will be scaled and transformed as usual if we do NOT use ItemIgnoresTransformations flag. So we also need to rescale the boundingRect to maintain the view independence effect.
To maintain the view-independent bounding rectangle turns out to be quite easy: just grab the scaling factor from deviceTransform(m_view->viewportTransform()).inverted().m11() and multiply this constant to your local coordinate bounding rectangle. For example:
qreal m = this->deviceTransform(m_view->viewportTransform()).inverted().m11();
return QRectF(m*(m_shapeX), m*(m_shapeY),
m*(m_shapeR), m*(m_shapeR));
here is a solution I devised of very moderate complexity :
1) Get the boundingRect() of the parent and map it to scene
2) take the minimum X and Y of this list of points, this is the real origin of your item, in scene coordinates
3) set the position of the child
In Pyside :
br = parent.mapToScene(parent.boundingRect())
realX = min([item.x() for item in br])
realY = min([item.y() for item in br])
child.setPos(parent.mapFromScene(realX, realY)) #modify according to need
A long time ago I tried to find method how to stick QDialog window to screen borders for my small projects like Skype windows do it, but I failed. May be I was looking this code not in the right place, so now I'm looking the solution here, on stack! :)
So, does any one have a deal with some kind of such code, links, samples?
In my opinion, we have to reimplement QDialog moveEvent function, like below, but that code does not working:
void CDialog::moveEvent(QMoveEvent * event) {
QRect wndRect;
int leftTaskbar = 0, rightTaskbar = 0, topTaskbar = 0, bottomTaskbar = 0;
// int top = 0, left = 0, right = 0, bottom = 0;
wndRect = this->frameGeometry();
// Screen resolution
int screenWidth = QApplication::desktop()->width();
int screenHeight = QApplication::desktop()->height();
int wndWidth = wndRect.right() - wndRect.left();
int wndHeight = wndRect.bottom() - wndRect.top();
int posX = event->pos().x();
int posY = event->pos().y();
// Snap to screen border
// Left border
if (posX >= -m_nXOffset + leftTaskbar &&
posX <= leftTaskbar + m_nXOffset) {
//left = leftTaskbar;
this->move(leftTaskbar, posY);
return;
}
// Top border
if (posY >= -m_nYOffset &&
posY <= topTaskbar + m_nYOffset) {
//top = topTaskbar;
this->move(posX, topTaskbar);
return;
}
// Right border
if (posX + wndWidth <= screenWidth - rightTaskbar + m_nXOffset &&
posX + wndWidth >= screenWidth - rightTaskbar - m_nXOffset) {
//right = screenWidth - rightTaskbar - wndWidth;
this->move(screenWidth - rightTaskbar - wndWidth, posY);
return;
}
// Bottom border
if (posY + wndHeight <= screenHeight - bottomTaskbar + m_nYOffset &&
posY + wndHeight >= screenHeight - bottomTaskbar - m_nYOffset) {
//bottom = screenHeight - bottomTaskbar - wndHeight;
this->move(posX, screenHeight - bottomTaskbar - wndHeight);
return;
}
QDialog::moveEvent(event);
}
Thanks.
As you thought you can achieve this in the moveEvent function.
I guess the following code do the trick but since I have nothing to test here I will write some pseudo code:
First get the available screen area:
const QRect screen = QApplication::availableGeometry(this);
// This get the screen rect where you can drag a dialog
Then get the position of your dialog relative to the desktop (if your dialog is a child of an other widget, you need to transform coordinates from widget relative to desktop relative):
const QRect dialog = geometry();
// Do here transformation
Now test if dialog is near screen border
if( abs(dialog.left()-screen.left() < OFFSET )
move(screen.left(), dialog.top();
else if( abs(dialog.top()-screen.top() < OFFSET )
move(dialog.left(), screen.top() )
// etc. for the 2 other cases
Let me know if it works
In the pos property description from the QWidget documentation, there is the following warning about moving a window inside the move event handling method.
Warning: Calling move() or setGeometry() inside moveEvent() can
lead to infinite recursion.
That said, there is no proper way to stick the dialog window inside the screen border.
Note :
The behavior you observed in KDE comes from the Window Manager. Actually, the Window Manager is the one that arranges the application windows (like dialog boxes) to show them on the screen. The KDE Window Manager has an option to make all application windows (called client) stick to the border.
I want the size of the QTableView to be the same as the table it contains (and fixed) so that it does not have a scrollbar
What you could do is calculate your tableview columns widths according to the data they have (or you can just call resizeColumnToContents for each column to size it to its content). Then change the tableview width to be equal or more then total width of columns + vertical header if shown. You would also need to track model changes and adjust your tableview width + if horizontal header is shown you can track columns resize events and adjust them again. Below is some sample code for this:
initialization:
// add 3 columns to the tableview control
tableModel->insertColumn(0, QModelIndex());
tableModel->insertColumn(1, QModelIndex());
tableModel->insertColumn(2, QModelIndex());
...
// switch off horizonatal scrollbar; though this is not really needed here
ui->tableView->setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
// adjust size; see code below
adjustTableSize();
// connect to the horizontal header resize event (non needed if header is not shown)
connect(ui->tableView->horizontalHeader(),SIGNAL(sectionResized(int,int,int)), this,
SLOT(updateSectionWidth(int,int,int)));
// connect to the model's datachange event
connect(ui->tableView->model(), SIGNAL(dataChanged(QModelIndex,QModelIndex)),
this, SLOT(dataChanged(QModelIndex,QModelIndex)));
adjust tableview size:
void MainWindow::adjustTableSize()
{
ui->tableView->resizeColumnToContents(0);
ui->tableView->resizeColumnToContents(1);
ui->tableView->resizeColumnToContents(2);
QRect rect = ui->tableView->geometry();
rect.setWidth(2 + ui->tableView->verticalHeader()->width() +
ui->tableView->columnWidth(0) + ui->tableView->columnWidth(1) + ui->tableView->columnWidth(2));
ui->tableView->setGeometry(rect);
}
process model change
void MainWindow::dataChanged(const QModelIndex &topLeft, const QModelIndex &bottomRight)
{
adjustTableSize();
}
process horizontal header resize
void MainWindow::updateSectionWidth(int logicalIndex, int, int newSize)
{
adjustTableSize();
}
hope this helps, regards
sum(item.sizeHint()+headeroffset+border) doesn't work well for me, there's probably spacing between the items, even if grid is off. So I made adjustment this way:
view->resizeRowsToContents();
view->resizeColumnsToContents();
QAbstractItemModel* model = view->model();
QHeaderView* horHeader = view->horizontalHeader();
QHeaderView* verHeader = view->verticalHeader();
int rows = model->rowCount();
int cols = model->columnCount();
int x = horHeader->sectionViewportPosition(cols-1) + horHeader->offset()
+ horHeader->sectionSize(cols-1) + 1;
int y = verHeader->sectionViewportPosition(rows-1) + verHeader->offset()
+ verHeader->sectionSize(rows-1) + 1;
QPoint p = view->viewport()->mapToParent(QPoint(x,y));
QRect g = view->geometry();
g.setSize(QSize(p.x(),p.y()));
view->setGeometry(g);
Should work if the last column and last row is visible.
I tried serge_gubenko answer but I didn't work for me (Partly because I wanted to rezise both Height and Width)... so I altered it; To avoid the table being resized by layouts or parent widgets you will need this:
ui->tableView->setSizePolicy(QSizePolicy::Preferred,QSizePolicy::Fixed);
Then:
ui->tableView->setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
ui->tableView->setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
QRect rect = ui->tableView->geometry();
int width = 2,length = 2;
for(int col = 0;col<proxySortModel->columnCount();++col){
if(!ui->tableView->isColumnHidden(col))
width += ui->tableView->columnWidth(col);
}
for(int row =0;row<proxySortModel->rowCount();++row)
length += ui->tableView->rowHeight(row);
rect.setWidth(width);
rect.setHeight(length);
ui->tableView->setGeometry(rect);
I hope this helps someone.