Resources
NUI provides several ways to handle resource images. This tutorial describes the use of Image resources in NUI.
Overview
Resources in NUI can apply Images or three-dimensional Models.
The common method to access these resources is through Visuals. Controls use these visuals to display what is required.
See ImageView tutorial.
Loading images
Images are defined by an URL which can be local or remote (internet). The following formats are supported:
| Supported image formats | extentsion |
|---|---|
| Bitmap | .bmp |
| Gif | .gif |
| Jpeg | .jpeg |
| Khronos Texture | .ktx |
| PNG | .png |
| Mircosoft Icons | .ico |
| WAP Bitmap | .wbmp |
Controls should process the provided URL and internally create the matching Image Visual. Visual creation automatically determines whether the image is N_PATCH, SVG, or GIF, which is not a regular image from the image data.
Image Properties
| Property Name | Description |
|---|---|
AlphaMaskURL |
URL to an image that will mask the main content image. |
CropToMask |
Flag to determine if main content image should crop to match mask size. |
FittingMode |
By default the image will shrink to fit the DesiredHeight and DesiredWidth, other modes available. |
SamplingMode |
The type of sampling to be used. Default is Box. |
DesiredWidth |
The width you would like the Image to be. Affected by FittingMode. |
DesiredHeight |
The height you would like the Image to be. Affected by FittingMode. |
SynchronousLoading |
If loading should block the execution thread, disabled by Default. |
PixelArea |
Can be set to display only a portion of the Image. |
WrapModeU |
Define how sampling should behave for u coordinate. |
WrapModeV |
Define how sampling should behave for v coordinate. |
N-Patch only properties
| Property Name | Description |
|---|---|
Border |
Specifies border values for N-Patch images. |
BorderOnly |
Specifies if only borders to be shown for N-Patch images. |
Animated GIF only properties
| Property Name | Description |
|---|---|
BatchSize |
Number of Images to decode before animation starts, Default is one. |
CacheSize |
Number of images to keep cached, can increase or decrease depending on memory available. |
FrameDelay |
Millisecond delay between frames. |
Synchronous loading has niche uses, for example, ensure image has loaded before continuing to execute application code,
the common use is to connect to the control’s ResourceReady and perform operations at that point.
Reducing image memory footprint
An application that loads images can also display images at a lower resolution than their native resolution.
To support this, DALi can resize an image at load time so that its in-memory copy uses less space and its visual quality benefits from being prefiltered.
The FittingMode namespace provides four algorithms, which can be used to fit an image to a desired rectangle, a desired width, or a desired height.
The fitting modes and suggested use cases are as follows:
| Fitting mode | Suggested use case |
|---|---|
ShrinkToFit |
Full screen image display: limit the loaded image resolution to the device resolution, but show all of the image. |
ScaleToFill |
Thumbnail gallery grid: limit the loaded image resolution to the screen tile, filling the whole tile but losing a few pixels to match the tile shape. |
FitWidth |
Image columns: limit the loaded image resolution to the column width. |
FitHeight |
Image rows: limit the loaded image resolution to the row height. |
Related Information
- Dependencies
- Tizen 4.0 and Higher