ResourceHandler Class
The ResourceHandler class provides functionality to handle custom resources within studio design mode. More...
| Header: | #include <CDPBaseWidgets/ResourceHandler.h> |
Public Functions
| ResourceHandler(ParserSVG *svg = 0) | |
| bool | addPropertyToExecuteAfterTimedSvg(const QString &name, const QVariant &value, int postfix = 0) |
| void | setParser(ParserSVG *svg) |
| virtual void | setSvgFile(QString svg) |
Static Public Members
| int | waitMs() |
| int | waitOrderMs() |
Protected Functions
| virtual void | processQueuedProperties() |
| virtual void | processSvgFile(QString svgFile) = 0 |
Detailed Description
The ResourceHandler class provides functionality to handle custom resources within studio design mode.
Resource handling in design mode is required as resource files added to the project is not available when the form is loaded. Most of the widgets create pixmaps to minimize painting operations in the paintEvent. Hence, when the resource is not found, the widget will paint the fallback resource instead of the one you actually wanted. Adding an initial delay as provided by this class should ensure that the resource is available and ready for use.
Some widgets require multiple functions to be timed. In that scenario, the timeout values of this class can be used directly instead of implementing the virtual functions.
Also, widgets that calculate size based on resources will get wrong initial size and show default/wrong graphics while being dragged from the widget panel. To solve this, the widget needs to set the resource just before the sizeHint function is executed. At this point the resource is most likely, but not always, available. Hence, only executing resource loading functions from the sizeHint function is not enough. The timers are required in addition.
QSize CDPBaseSlider::sizeHint() const { if(m_svg.svgOutOfDate()) const_cast<CDPBaseSlider*>(this)->processSvgFile(m_svg.svgFileName()); ...
The timeouts can be overrided by placing a file, resourcehandler.ini, in the studio working directory. To change the timeouts used when running an application, place the file in the Application directory next to the executable. The file contains a main waiting time and a timeout to ensure that timeouts follow a specific order:
WaitMs = 1500 WaitOrderMs = 500
Member Function Documentation
ResourceHandler::ResourceHandler(ParserSVG *svg = 0)
Default constructs an instance of ResourceHandler.
bool ResourceHandler::addPropertyToExecuteAfterTimedSvg(const QString &name, const QVariant &value, int postfix = 0)
Add properties to queue if SVG timer is running.
This ensures that properties are executed in correct order after svgFile is executed. The property name and value is provided in the name and value arguments. Use the postfix argument to add a postfix number greater than zero to the property name.
Returns true if the property was added to the execution queue. A false return value means that the timer is not running and can be executed directly. The function will not set the property after returning false.
[virtual protected] void ResourceHandler::processQueuedProperties()
[pure virtual protected] void ResourceHandler::processSvgFile(QString svgFile)
Function that is executed after a timeout to ensure that the resource is available when it is run. This is where you will typically also execute loading of pixmaps. The svgFile argument contains the full svg file name.
void ResourceHandler::processSvgFile(QString svgFile) { if (m_svg.updateRequired(svgFile, this)) { m_svg = m_svg.parseSvg(svgFile); ... } }
void ResourceHandler::setParser(ParserSVG *svg)
[virtual] void ResourceHandler::setSvgFile(QString svg)
[static] int ResourceHandler::waitMs()
[static] int ResourceHandler::waitOrderMs()
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