So you want to develop apps for mobile and embedded devices using Qt. Excellent choice, as Qt was made for cross-platform development. To get you started, we will run through the basic procedure of using Qt Creator to create, build and run an application. We will briefly examine different aspects to consider when creating mobile and embedded apps, such as how to use Qt Creator to add a menu. Adding a QWidget in the designer is not that difficult, and I will show you how.

Qt has a long history of running on mobile devices, starting with Qt Embedded, which was initially released in 2000. Qt Embedded was the base framework for the UI Qtopia, which was initially released on the Sharp Zaurus on the SL-5000D developer edition.

These days, you can develop an application using Qt and sell it in the iOS App Store, Android Google Play store, or other Linux mobile phones. Qt...

Porting applications which were developed for the desktop to run on smaller mobile devices can be a daunting task, depending on the application. Even creating new apps for mobiles, a few considerations need to be made, such as differences in screen resolution, memory constraints, and handling orientation changes. Touch screens add another fantastic way to offer touch gestures and can be challenging due to the differences in the size of a finger as point compared to a mouse pointer. Then there are sensors, GPS and networking to contemplate! 

As you can see in the previous images in the Add QListView section, the application paradigms are fairly different...

Considering that mobile phones come in all shapes and sizes, it would be ridiculous to need to provide a different package for every different screen resolution. Hence we will use dynamic layouts.

Qt Widgets have support for this using classes such as QVBoxLayout and QGridLayout.

Qt Creator's designer is the easiest way to develop dynamic layouts. Let's go through how we can do that.

To set up a layout, we position a widget on the application form, and press Command or Control on the keyboard while selecting the widgets that we want to put in a layout. Here are two QPushButtons selected for use:

Next, click on the Horizontal Layout icon highlighted here:

You will then see the two widgets enclosed by a thin...

QGraphicsView, QGraphicScene and QGraphicsItem provide a way for applications based on Qt Widgets to show 2D graphics.

Every QGraphicsView needs a QGraphicsScene. Every QGraphicsScene needs one or more QGraphicsItem.

QGraphicsItem can be any of the following: 

• QGraphicsEllipseItem
• QGraphicsLineItem
• QGraphicsLineItem
• QGraphicsPathItem
• QGraphicsPixmapItem
• QGraphicsPolygonItem
• QGraphicsRectItem
• QGraphicsSimpleTextItem
• QGraphicsTextItem

Qt Designer has support for adding QGraphicsView . You can follow these steps to do so:

1. Drag the QGraphicsView to a new application form and fill the form with a QGridLayout like we did before.

2. Implement a QGraphicsScene in the source code and add it to the QGraphicsView

QGraphicsScene...

In this chapter we covered some of the issues facing mobile and embedded developers when trying to develop for smaller display devices, and how  QStyleSheets can be used to change the interface at runtime to adapt itself for using touchscreen inputs.

We discussed storage and memory space requirements, and the need to configure unneeded features out of Qt to make it have a smaller footprint.

We went through handling orientation changes and discussed using screen gestures such as Pinch and Swipe.

We learning how to use Qt Designer to add QLayouts to create dynamically resizing applications.

Finally, we discussed how to use QGraphicsView to utilize graphical elements such as graphical text and images.

Next, we will go through the next best thing since sliced bread for mobile and embedded development—Qt Quick and QML. Then we&apos...