qt

QScrollArea widget content promoted to QWidget

Hi folks, First of all, thanks for you time reading my question. I created my own Qt Widget (parent of QWidget) and has a QImage "inside" to manipulate images. The problem I have is the following: when I promote the content of a QScrollArea (QDesigner) to my widget, the scroll features doesn't works; I haven't any scroll bar or I can't...

QT4, paginated showing elements

I am going to write an application that uses QT4 (with C++ or python it isnt important in that moment). One of functionality is "Showing all items in database". One item has a Title, author, description and photo (constant size) And there could be very many items. Let's say 400. There won't be enough space to show'em all at once time. ...

QT Transparent Layout

Hello, I am using a vertical layout (QVBoxLayout) to manage buttons. I would like to make its background color as 50% black transparent. Is it possible ? sw ...

C++, Qt - How do I get rid of dll dependencies?

Hello! I have compiled my Qt application and now have the following question - now my built project requires QtCore4.dll and QtGui4.dll to be located at the same folder where the .exe file is. (I built my project using MSVS2008 with Qt addon) Q: Is there any way to combine my final application with these .dll files so that they make o...

How to use custom drawing in QGraphicsViews in PyQt?

I need to view QGraphicsScene in 2 QGraphicsViews with condition that they have different scale factors for items in scene. Closest function which I found is drawItems(), but as far I can understand, it must be called manually. How to repaint views automatically? I have these two code fragments in program: class TGraphicsView(QGraphicsV...

Qt not displaying PNG images on Linux

Hi, I have a software written using Qt which is meant to work on both Windows and Linux. I use PNG images as icons for my QActions, embedded in a resource. I have the following tree directory: / resources/ icons.qrc image.png Here is the content of icons.qrc: <RCC> <qresource prefix="/resources" lang="fr"> <file al...

Using custom coordinates with QGraphicsScene

I am experimenting with a WYSIWYG editor that allows a user to draw shapes on a page and the Qt graphics scene support seems perfect for this. However, instead of working in pixels I want all my QGraphicsItem objects to work in tenths of a millimetre but I don't know how to achieve this. For example: // Create a scene that is the size...

QTableWidget::itemAt() returns seemingly random items

I've just started using Qt, so please bear with me. When I use QTableWidget->getItemAt(), it returns a different item from if I used currentItemChanged and clicked the same item. I believe it's necessary to use itemAt() since I need to get the first column of whatever row was clicked. Some example code is below: MainWindow::MainWindo...

Drawing widgets (such as buttons) over QGraphicsView

How do I draw interactive widgets such as QButtons and Line Edits over a QGraphicsView? For ex, I have selected a region over an image in an image editing app which displays an image with QGraphicsView, and I want to annotate this region with a name. So I want to have a Line edit and two buttons (Cross and Tick) below this rectangular ...

What exactly are signals and slots in Qt?

I know how they work conceptually, but how are signals and slots implemented in the Qt framework? Qt Creator treats them as keywords, but are they simply a set of macros, or is a special pre-processor required before these source files can be compiled? In other words, if I use Qt's signal/slot features in my code, can I easily compile ...

Porting QT application from Linux to Windows?

Greetings all, We are developing a QT application (QT 4.6 LGPL version) in Linux platform.All the libraries we use are cross-platform. Now we want to port it into Windows and continue develop in Windows. My questions are: Which compiler should we use ,Can we use MinGW or Visual C++ compiler? 2.If its Visual C++ compiler, which Visua...

QPainter paints garbage

Fragment of program code: def add_link(Item0Num, Item1Num): global Mw, View # Mw - MainWindow if Item0Num != Item1Num and not link_exists(Item0Num, Item1Num): append( links_to(Item1Num), Item0Num ) append( links_from(Item0Num), Item1Num ) LinkGi = TLinkGi() Mw.Scene.addItem(LinkGi) LinkGi....

Configuring gcc compiler switches in Qt / QtCreator / QMake

I recently tried to use Qt Creator 1.3.2 / Qt 4.6.2 / gcc 4.4.0 (32-bit version) on Windows 7 (64-bit) to compile an application using some of the experimental C++0x extensions and encountered the following (fatal) error: This file requires compiler and library support for the upcoming ISO C++ standard, C++0x. This support is currently ...

Does Qt use ClearType for rendering text in Windows?

Does Qt use ClearType for rendering text (on Windows), and if so, what do I need to set to enable ClearType support? ...

How to know coordinates in a real image from a scaled image.

Hi folks, First of all thanks for your time reading my question :-) I have an original image (w': 2124, h': 3204) and the same image scaled (w: 512, h: 768). The ratio for width is 4.14 (rw) and the ratio for height is 4.17 (rh). I'm trying to know the coordinates (x', y') in the original image when I receive the coordinates in the s...

Qt mac : How does the layout differs from other OSes

Qt is a nice framework which allows people to develop something once and it will works for the 3 main OSes. But from times to times, there is some differences in the layout: placing some widgets does not have the same behavior as in windows or linux. Did you observe weird behavior ? on which Widgets ? how did you corrected this ? Than...

Classes to use for a flexible image selection/tagging widget in Qt

Hello, I'm new with Qt and am looking for advice on how to structure this. I want a flexible widget that can display a set of images (normally read from a directory but other sources too) and let the user select images with the arrow keys and/or mouse and also apply custom tags. For example there might be 5 tags defined by the applicat...

QT and QwebKit can i load javascript file as resource file and use it ?

Hello all i wander if i can load javascript as resource file to use in QwebKit well its dont have to be resource file , i just looking for a method to emmbed js files in to my application ...

Qt and finding partial matches in a QList

I have a struct viz: struct NameKey { std::string fullName; std::string probeName; std::string format; std::string source; } which are held in a QList: QList<NameKey> keyList; what I need to do is find an occurence in keyList of a partial match where the search is for a NameKey that only has two ...

Qt - QPushButton text formatting

I have a QPushButton and on that I have a text and and icon. I want to make the text on the button to be bold and red. Looked at other forums, googled and lost my hope. Seems there is no way to do that if the button has an icon (of course if you don't creat a new icon wich is text+former icon). Is that the only way? Anyone has a better i...