ImageSelectControl
A picture the user can replace: the thumbnail, a button to clear it, and a file chooser behind the picture itself.
ImageSelectControl avatar = new ImageSelectControl();
avatar.setDisplayDimensions(new Dimension(96, 96));
avatar.setMaxDimensions(new Dimension(512, 512));
fb.label("Your avatar").control(avatar);
The two sizes
They are different things, and both matter:
| Method | What it is |
|---|---|
setDisplayDimensions(Dimension) |
how big the thumbnail on the screen is (default 32x32) |
setMaxDimensions(Dimension) |
what an uploaded picture is resized down to before it is kept (default 1024x1024) |
So a control that shows a 96-pixel avatar but keeps a 512-pixel picture sets both. The second one is the one that decides what ends up in the database.
The value
It is an IControl<IUIImage>, so it behaves like every other control:
getValue(), setValue(), setMandatory(), setReadOnly(), setDisabled(),
setOnValueChanged(), and a FormBuilder binds it to a property like any other.
What it produces is a LoadedImage over the uploaded file, resized to
maxDimensions, and that file is registered as a temporary file of the
conversation:
The uploaded file is deleted when the conversation ends. A page that wants to keep the picture has to read it and store it - in a blob, on disk, wherever - while the user is still on the page. Nothing is saved for you.
| Method | What it does |
|---|---|
setEmptyIcon(IIconRef) |
what is shown when there is no picture (default: the theme's empty icon) |
setEmptyIcon(Class<?>, String) |
the same, as a java resource beside a class |
What the user can do
Pressing the picture opens the file chooser; choosing a file uploads it straight
away and the thumbnail becomes the new picture. The button next to it clears the
value. Both fire onValueChanged.
The chooser accepts .jpg, .jpeg, .png and .gif, at up to 10MB - that is
fixed in the control, not a property. Anything the picture is not, or anything
ImageMagick cannot identify, comes back as a flare saying the image is invalid,
and the old value stays.
Just showing one
For the same picture without the editing - a list of avatars, a detail screen
that may not be changed - use DisplayImage, which
is the read-only half of the same mechanism and takes the same IUIImage.