Android and QT-extended

AllArticleAll rights reserved by the site and original author are permitted to be reproduced only when the copyright information, original text links, and original text authors are retained. Do not delete or modify the original content for commercial purposes. Thank you for your cooperation.

Link to the original article: Android and QT-extended

Currently, QT-extended has stopped development, but Nokia is preparing to develop a new QT-mobility as an alternative tool. I believe many excellent design concepts in QT-extended will still be inherited. We look forward to a better performance of QT in Nokia.

As a new mobile development platform, Android and QT-extended are designed to focus developers on the implementation of software functions, rather than spending a lot of energy on system resource management. This is the biggest difference from the Symbian platform. In the era of Symbian design, memory/CPU resources were scarce. Therefore, developers should not only design the software architecture, but also be ready to handle insufficient memory at any time. As the hardware performance improves, Nokia intends to replace QT with Symbian.

Although Android and QT-extended use different terms to describe these design methods, they are essentially the same, so let's take a look at their corresponding relationship.

Application configuration fileAndroidmanifest. xml vs appname. Desktop
Although Android does not runProgramIt is called an application or an activity, but it is not a problem to use an application to understand it. Androidmanifest. XML is used to start the application and manage corresponding resources. In QT-extended, appname. Desktop is used to complete the corresponding functions. The appname varies with the application name. The launcher started by the application finds the corresponding binary through the. desktop file.CodeThen start the process.

External Service Interface intentfilter vs Service
The interface of the external service implements the following functions. For example, if you see a link to an audio file on the current page, When you click the link, the external service program is called to implement this function, however, the current Application Designer does not know which application of the system is used to complete this function. Only one request like playing audio can be sent, the system determines which application executes the playback function. The advantage of this design is that the system components can be easily replaced. Android uses intent and intentfilter to implement this function. Qt-extended is implemented using service.

Application LifecycleActivity manager vs memorymanager
When the memory space is insufficient, the system requires a response to close unnecessary applications. Android uses the activity manager to determine which applications to close based on the status of acitivity. Qt-extended uses memorymanager in the startup service process to monitor the memory status and manage applications.

Background applicationsService vs qcop message
Background applications are used to run applications that do not require GUI, such as online downloads and music playing. Android starts the service to complete this function, while QT-extended can send a reference request to the system through qcop, such as dialing and downloading.

Broadcast ServiceBroadcastreceiver vs registerqcopchannel
Broadcast service refers to the broadcast action that the system uses when a certain state change occurs to most applications to respond accordingly. For example, when the battery power is low and external devices such as USB are connected. Android uses broadcastreceiver to receive system notifications, and other activities or services can respond accordingly. The Design of QT-extended is a little different. When the external status changes, messages will be sent to a qcop channel of the system. If you are interested in messages on this channel, you can register a listener on the channel to respond to the listener in a timely manner.

This article is a comparison based on the platform framework, mainly Android vs QT-extended. For different designs on the basic software code, such as the view data mode and observer mode, we can look forward to the next article Android vs QT.