Gallery QML Plugin

Overview

The QML Gallery plugin contains features that can be used to search for and retrieve documents from the Document Gallery.

Search Filters

Searching is performed by creating a filter based on a derived gallery filter class. This results in a set of Gallery QML elements for filtering. The Search parameters can be set by specifying property values which refer to the meta-data of the documents. For example, a meta-data key might be "author". Then, for example, by setting the filter property to "author" and the value to "torvalds" the filter is ready to enable a search for all documents authored by "torvalds".

Available filters include

QML GalleryContainsFilter Element	The GalleryContainsFilter element provides a filter which tests if a meta-data property contains a string.
QML GalleryEndsWithFilter Element	The GalleryEndsWithFilter element provides a filter which tests if a meta-data property ends with a string.
QML GalleryEqualsFilter Element	The GalleryEqualsFilter element provides a filter which tests if a meta-data property is equal to a value.
QML GalleryFilterIntersection Element	The GalleryFilterIntersection elements provides a intersection of gallery filters.
QML GalleryFilterUnion Element	The GalleryFilterUnion elements provides a union of gallery filters.
QML GalleryGreaterThanEqualsFilter Element	The GalleryGreaterThanEqualsFilter element provides a filter which tests if a meta-data property is greater than or equal to a value.
QML GalleryGreaterThanFilter Element	The GalleryGreaterThanFilter element provides a filter which tests if a meta-data property is greater than a value.
QML GalleryLessThanEqualsFilter Element	The GalleryLessThanEqualsFilter element provides a filter which tests if a meta-data property is less than or equal to a value.
QML GalleryLessThanFilter Element	The GalleryLessThanFilter element provides a filter which tests if a meta-data property is less than a value.
QML GalleryStartsWithFilter Element	The GalleryStartsWithFilter element provides a filter which tests if a meta-data property starts with a string.
QML GalleryWildcardFilter Element	The GalleryWildcardFilter element provides a filter which tests a meta-data property against a value using wildcard matching.

There is nothing to prevent the developer creating a number of filters. Then she could use either a GalleryFilterUnion or a GalleryFilterIntersection to find the result of OR-ing or AND-ing the criteria respectively to create a more complex search requirement.

Gallery Item

DocumentGalleryItems are elements that are a means to request information about a single item from a gallery. The information may include monitoring the state of the request, reading the meta-data for the document or writing meta-data.

When a request is made the status property contains the current status of the request including whether it is active or canceled.

Progress of the request is available through the qreal (floating point number) item property progress.

Query Requests

The DocumentGalleryModel element is used to perform the requests on a document gallery. The following snippet of QML from the DocumentGalleryModel documentation is worth a closer look because it puts together several of the elements discussed in this overview.

 import QtMobility.gallery 1.1

     ...

     model: DocumentGalleryModel {
         rootType: DocumentGallery.Image
         properties: ["url"]
         filter: GalleryWildcardFilter {
             property: "fileName";
             value: "*.jpg";
         }
     }

     ...

Here we have a model using a DocumentGalleryQueryModel. Within Qt the term 'model' usually refers to the Model part of a variation on the Model-View-Controller design pattern. In essence it is a data-oriented part of the Gallery query object, what data types are part of this query. For a clearer understanding see the Qt documentation.

Classes

QML DocumentGalleryItem Element	The DocumentGalleryItem element allows you to request information about a single item from the document gallery
QML DocumentGalleryModel Element	The DocumentGalleryModel element is used to specify a model containing items from the document gallery.
QML DocumentGalleryType Element	The DocumentGalleryType element allows you to request information about an item type from the document gallery.
QML GalleryContainsFilter Element	The GalleryContainsFilter element provides a filter which tests if a meta-data property contains a string.
QML GalleryEndsWithFilter Element	The GalleryEndsWithFilter element provides a filter which tests if a meta-data property ends with a string.
QML GalleryEqualsFilter Element	The GalleryEqualsFilter element provides a filter which tests if a meta-data property is equal to a value.
QML GalleryFilterIntersection Element	The GalleryFilterIntersection elements provides a intersection of gallery filters.
QML GalleryFilterUnion Element	The GalleryFilterUnion elements provides a union of gallery filters.
QML GalleryGreaterThanEqualsFilter Element	The GalleryGreaterThanEqualsFilter element provides a filter which tests if a meta-data property is greater than or equal to a value.
QML GalleryGreaterThanFilter Element	The GalleryGreaterThanFilter element provides a filter which tests if a meta-data property is greater than a value.
QML GalleryLessThanEqualsFilter Element	The GalleryLessThanEqualsFilter element provides a filter which tests if a meta-data property is less than or equal to a value.
QML GalleryLessThanFilter Element	The GalleryLessThanFilter element provides a filter which tests if a meta-data property is less than a value.
QML GalleryStartsWithFilter Element	The GalleryStartsWithFilter element provides a filter which tests if a meta-data property starts with a string.
QML GalleryWildcardFilter Element	The GalleryWildcardFilter element provides a filter which tests a meta-data property against a value using wildcard matching.