I just begin to work on making a layout with Grid. I tried to make it using the HBoxlayout and VBoxlayout. But How to set the position of the layout. I searched out and I found the setAlignment option but it isn't working on it.
So how to do its postioning of layouts like the image?
this is the layout I want to make
check this out
#include "mainscreen.h"
#include "ui_mainscreen.h"
#include<QLayout>
#include<QPushButton>
MainScreen::MainScreen(QWidget *parent) :
QWidget(parent),
ui(new Ui::MainScreen)
{
ui->setupUi(this);
QGridLayout *layout=new QGridLayout;
QHBoxLayout *hlayout=new QHBoxLayout;
QPushButton *x=new QPushButton;
hlayout->setAlignment(Qt::AlignTop);
hlayout->addWidget(x);
layout->addChildLayout(hlayout);
this->setLayout(layout);
this->show();
}
MainScreen::~MainScreen()
{
delete ui;
}
You can find good information about Layout in this Tutorial from Qt: http://doc.qt.io/qt-5/qtwidgets-layouts-basiclayouts-example.html
Two things that are important for your Layout:
You need to nest several layout. Themain layout will be a VBoxlayout that contains the top and bottom Widget and one HBoxLayout in the middle. The HBoxLayout contain the other two widgets.
Two get different size for the two middle widgtes you need to give either a Stretch factor to the Layout or define sizes for the widgets.
You may consider doing the following
QHBoxLayout *TopLayout = new QHBoxLayout;
QHBoxLayout *BottomLayout = new QHBoxLayout;
QHBoxLayout *MiddleLayout = new QHBoxLayout;
QVBoxLayout *mainLayout = new QVBoxLayout;
QPushButton *topBtn = new QPushButton;
QPushButton *bottomBtn = new QPushButton;
QPushButton *LeftMiddleBtn = new QPushButton;
QPushButton *RightMiddleBtn = new QPushButton;
TopLayout->addWidget(topBtn);
BottomLayout->addWidget(bottomBtn);
// order matters here (i.e. the first addWidget will be placed in the left)
MiddleLayout->addWidget(LeftMiddleBtn);
MiddleLayout->addWidget(RightMiddleBtn);
// order matters here
mainLayout->addLayout(TopLayout);
mainLayout->addLayout(MiddleLayout);
mainLayout->addLayout(BottomLayout);
setLayout(mainLayout);
More convenient and right approach is to use Qt Designer or Qt Creator for this matter.
QMainWindow is a spatial case. It already has a layout set and it is impossible to change layout in widget! Reason is that QMainWindow has lots of other functionalities like menu, docking, status bar.
So how to make it work?
You have to set central widget:
MainScreen::MainScreen(QWidget *parent) :
QWidget(parent),
ui(new Ui::MainScreen)
{
ui->setupUi(this);
auto widget = new QWidget();
setCentalWidget(widget);
auto vLayout = new QVBoxLayout(widget);
// add your stuff here
// some example for testing:
vLayout->addWidget(new QButton("Test button"));
vLayout->addWidget(new QLabel("Nice label"));
vLayout->addWidget(new QTextEdit);
}
Also you are doing something wrong since this line ui->setupUi(this); indicates that you are using Qt Designer (design ui by mouse) and this means that layout should not be setup directly by code!
Related
I want to implement a simple QT example: click the QPushButton to display a paragraph of text.
Like this:
I know there are many ways to implement it, but I don't know what's wrong with my code.
QPushButton *btn = new QPushButton;
//btn->show();
btn->setParent(this);
btn->setText("button 1");
QLabel *la = new QLabel(this);
connect(btn,&QPushButton::clicked,la,&QLabel::setText("show me"));
Anyone who can help me？
The idea is to create the QLabel with a predefined text and hide it. On clicking the button, show it. So, QLabel::hide and QLabel::show could be used here. Just take care of the coordinates where you show the label because it would overlap the button itself without layout or proper coordinates.
Example (mainwindow.cpp, constructor):
#include "mainwindow.h"
#include "ui_mainwindow.h"
MainWindow::MainWindow(QWidget *parent)
: QMainWindow(parent)
, ui(new Ui::MainWindow)
{
ui->setupUi(this);
setWindowTitle("My App"); // title bar text
QPushButton *btn = new QPushButton(this);
btn->setText("Click Me!");
QLabel *la = new QLabel(this);
la->setText("Show Me!"); // set label text in advance
la->move(100, 100); // set label position
la->hide(); // hide label on load
connect(btn, &QPushButton::clicked, la, &QLabel::show);
}
MainWindow::~MainWindow()
{
delete ui;
}
Output (after clicking the image):
I create interface dynamically when Application is run.
1) I have QTabWidget with 4 predefined tabs. But i must show only 1 or 2 tabs, in case of user shoice. On StackOverflow i learned, that i must keep all tabs in collection to add and destroit it.
I have QHash: twInputMethodsTabs = new QHash< int, QPair<QWidget*, QString> >();
First argument = index; Second = Tab Widget; Third = Tab Widget Caption Text;
2) I fill the collection like this:
for(int i = 0; i < ui->twInputMethods->children().length(); i++)
{
twInputMethodsTabs->insert(i, QPair<QWidget*, QString>(ui->twInputMethods->widget(i), ui->twInputMethods->tabText(i)));
}
3) I add new widget in the tab like this:
twInputMethodsTabs->value(1).first->layout()->addWidget(cmbbCommands);
4) How can i add new layout to this widget? I want to do like this:
QHBoxLayout *hblParams =new QHBoxLayout();
twInputMethodsTabs->value(1).first->layout()->addLayout(hblParams);
But it does not work, because layout() returns QLayout which havent addLayout() function. How i can do this?
Or how can i should change architecture of code to do this?
In this following code you get a widget (.first) and then select that widget's layout ->layout() and then add a Widget to that layout ->addWidget().
twInputMethodsTabs->value(1).first->layout()->addWidget(cmbbCommands);
In the following code you get a widget (.first) and then select that widget's layout ->layout() and try to set the layout on the layout.
twInputMethodsTabs->value(1).first->layout()->addLayout(hblParams);
Replacing the QLayout
To set the layout on the parent widget, you need to drop the ->layout():
twInputMethodsTabs->value(1).first->addLayout(hblParams);
Note that since you are now adding an empty layout to the widget, any widgets current in the previous layout will be lost, so you may need to re-add the widgets to the layout.
Adding new QLayout inside existing QLayout
If you want to add a layout into the existing layout, you cannot do this directly. QLayout can only accept QWidget via .addWidget(). However, you can apply a layout to an empty QWidget() and then add that to the layout. For example:
QWidget *w = new QWidget();
w.addLayout(hblParams);
twInputMethodsTabs->value(1).first->layout()->addWidget(w);
An alternative is to set the layout on the QWidget to a layout that does support .addLayout() such as QHBoxLayout or QVBoxLayout. For example:
QVBoxLayout *l = new QVBoxLayout();
cmbbCommands.setLayout(l); // Now has a layout that supports .addLayout
twInputMethodsTabs->value(1).first->layout()->addWidget(cmbbCommands);
Now the following should work because ->layout() returns a QVBoxLayout:
QHBoxLayout *hblParams =new QHBoxLayout();
twInputMethodsTabs->value(1).first->layout()->addLayout(hblParams);
I Hope, I get what you want to do:
twInputMethodsTabs->value(1).first->layout()->addWidget(cmbbCommands);
QHBoxLayout *hblParams =new QHBoxLayout();
QWidget *w = new QWidget(twInputMethodsTabs->value(1).first);
twInputMethodsTabs->value(1).first->layout()->addWidget(w);
w->addLayout(hblParams);
I just wrote the code here, so it is untested. However it should give you an idea what I tried to explain in my comment.
Cutted from "working" application:
WidgetA::WidgetA(QWidget *parent) : QWidget(parent)
{
QVBoxLayout *pLayout = new QVBoxLayout();
buildWidget(pLayout);
this->setLayout(pLayout);
}
void WidgetA::buildWidget(QVBoxLayout *layout){
for(int i=0; i<4; ++i){
this->buildSegments(layout);
}
}
void WidgetA::buildSegments(QVBoxLayout *layout){
QHBoxLayout *pHbl = new QHBoxLayout();
QLabel *pSegmentSize = new QLabel(this);
pSegmentSize->setText(tr("Segment Size(1,N)"));
QSpinBox *pSegments = new QSpinBox(this);
pHbl->addWidget(pSegmentSize);
pHbl->addWidget(pSegments);
layout->addItem(pHbl);
}
Read this one: Widgets Tutorial - Nested Layouts
I would like to make a QToolButton where the text is the left of its icon. I've tried to find related information, and tried things with:
button->setToolButtonStyle(Qt::ToolButtonTextBesideIcon);
but this sets the text to the right side of the button. I've looked into trying stylesheets, but text-alignment is only for push buttons. Is there any way to do this?
My highest-level goal is to make an interface bar which looks like this:
with a text label and image right beside it. Currently I'm using a toolbar with checkable toolbuttons because of the style (no border unless moused-over, still has the indent with checkable, contains text and an icon...). It's entirely possible that I'm using the wrong type widgets, so if I can't change the layout of this, is there any way to emulate this style?
This is what I currently have:
.
You can use QWidget::setLayoutDirection:
toolbar->setLayoutDirection(Qt::RightToLeft);
Your best bet is probably to create this functionality yourself in a QWidget. It should have a QLabel and a QToolButton (or QPushButton) arranged in a QHBoxLayout. Then you can add this custom widget to the toolbar using QToolBar::addWidget() or QToolBar::insertWidget().
Here's an example of a widget you could use:
#include <QtGui>
class CoolButton : public QWidget
{
public:
CoolButton(QWidget *parent = 0) : QWidget(parent)
{
QLabel *label = new QLabel("Hi!", this);
QToolButton *button = new QToolButton(this);
QHBoxLayout *layout = new QHBoxLayout;
layout->addWidget(label);
layout->addWidget(button);
setLayout(layout);
}
};
Currently I have QMenuBar with three QActions and it looks like this:
but I would like to get this (get some QActions right-aligned):
Is there a way to do this?
Probably the most simple solution to this particular problem is to use the corner widget. It can be used to place almost anything at the rightmost position, of course also a new menu bar:
QMenuBar *bar = new QMenuBar(ui->menuBar);
QMenu *menu = new QMenu("Test menu", bar);
bar->addMenu(menu);
QAction *action = new QAction("Test action", bar);
bar->addAction(action);
ui->menuBar->setCornerWidget(bar);
Result:
This is esp. helpful when the main menu is still to be edited in QDesigner...
Well one possible solution is here. But it involves implementing your own style (QStyle as I recall). However here is a snippet that I have just tried on mainwindow class:
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow) {
ui->setupUi(this);
QMenuBar *barLeft = new QMenuBar;
QMenuBar *barRight = new QMenuBar;
barLeft->addAction("Foo Left 1");
barLeft->addAction("Foo Left 2");
barRight->addAction("Foo Left 1");
barRight->addAction("Foo Left 2");
QHBoxLayout *mainMenuLayout = new QHBoxLayout;
mainMenuLayout->addWidget(barLeft);
mainMenuLayout->addWidget(barRight);
mainMenuLayout->setAlignment(barLeft, Qt::AlignLeft);
mainMenuLayout->setAlignment(barRight, Qt::AlignRight);
QWidget *central = new QWidget;
central->setLayout(mainMenuLayout);
setCentralWidget(central);
}
This should be suitable.
Here is what I am doing： mainwindow with MdiArea, and I add a scrollarea widget (which contains a image label) to MdiArea as a subwindow. It doesn't work (the picture doesn't show).
Here is my code:
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
QScrollArea sa;
QPixmap *image = new QPixmap("2.jpg");
QLabel* imageLabel = new QLabel();
imageLabel->setPixmap(*image);
sa.setWidget(imageLabel);
sa.show();
ui->mdiArea->addSubWindow(&sa);
}
But when I use a QLabel as subwindow directly, i.e. replace the last line with:
ui->mdiArea->addSubWindow(imageLabel);
it works perfectly.
Anyone know why this is happening?
QScrollArea sa;
This declares a QScrollArea on the stack. It gets destroyed immediately after the constructor finishes. Allocate it with new like you do for the other widgets and it should start working.
QScollArea *sa = new QScrollArea;
...
ui->mdiArea->addSubWindow(sa);
(And change the sa. to sa->.)