Annotation derived widgets

The class needs @GuiPlugin, so the Hop GUI scans it at startup, and getters and setters for every annotated field. Lombok @Getter and @Setter are the usual way to get those. A field that is saved also carries @HopMetadataProperty. The widget annotation does not persist anything.

Give the class a parent-id constant and put that same string on every widget. GuiCompositeWidgets looks widgets up by the runtime class name and this id, so the object you pass in has to be an instance of the @GuiPlugin class. Fields declared on a superclass are picked up, but they are registered under the plugin class.

A @GuiPlugin that is also metadata and lives in a plugin classloader group must set classLoaderGroup on @GuiPlugin. Without it the GUI loads a second copy of the class. GUI describes the failure.

type selects the control.

namingSchemeType marks a text widget as a name (file, folder, hop-variable, and so on) so the naming-scheme indicator is shown. FILENAME and FOLDER infer file and folder. An empty value on any other type means the widget is not a name.

By default the widgets of one parentId are a single flat form. Set group and the widgets are placed in a container instead. Repeat groupType on every field. The first value that is not NONE wins. If two fields ask for different types, the GUI logs an error and shows tabs.

group is the title. An i18n:: key is translated. groupOrder sorts the groups, again as a string, the same way order sorts fields. A field with an empty group lands in a group titled "General" when any sibling has a group.

Extend BaseTransformDialog or ActionDialog. In open(), create the shell, build the button bar, then add the widgets between the name and the OK button.

addScrolledComposite attaches a scrolled composite below the control you pass as the top (wTransformName in a transform dialog, wName in an action dialog) and above the control you pass as the bottom (wOk). The annotated widgets are created inside it, and the current values are copied in. getWidgetsContents on OK copies them back.

That is what keeps the dialog resizable with the buttons pinned under the fields. A flat row of `FormAttachment`s on the shell fights the button bar for the same vertical space, and the buttons end up on top of the lower widgets. Groups make this reliable. The tab folder fills the scrolled area, and each tab scrolls its own fields. The stack of boxes fills that same area. Its preferred height is the height of the fields put together, so a scrolled parent shows a scrollbar only when the fields themselves do not fit. Extra space is shared between the boxes, and a box scrolls its own fields when the dialog is too short for them.

Pass createCompositeWidgets a composite that is stretched to the bottom of the available area, with a bottom attachment at 100 percent. addScrolledComposite does this, from the name line down to the OK button. That stretch gives the boxes the extra space to share, and it squeezes a box until the box scrolls, when the dialog is short. A composite that only wraps the preferred height leaves every box at the height of its fields.

An action dialog has the same shape. ActionDbtDialog is the worked example for tabs plus an extra table.

A class annotated with @ConfigPlugin is laid out with the label above the control and the control at full width. Transform and action metadata keep the label on the left. The Database perspective options use the label-above layout because that class is a configuration plugin. Data set output uses the label on the left.

A metadata editor extends MetadataEditor. The name field is still created by the editor. The rest of the fields come from the metadata class, which is both @HopMetadata and @GuiPlugin.

NamingSchemeEditor is a compact example. It builds the name, registers one extra group, then creates the annotated widgets under the name:

setWidgetsContent() calls widgets.setWidgetsContents(metadata, parent, parentId). getWidgetsContent(metadata) calls widgets.getWidgetsContents(metadata, parentId).

Variable resolvers, database connection options, and the other metadata types that contribute fields to a shared editor use the same pair of annotations. The editor already owns the composite; the plugin only annotates its fields and sets parentId to the constant that editor looks up. For a variable resolver that constant is VariableResolver.GUI_PLUGIN_ELEMENT_PARENT_ID.

A @ConfigPlugin can expose the same options in the Configuration perspective. Annotate the picocli fields with @GuiPlugin on the class and @GuiWidgetElement on each field, and use ConfigPluginOptionsTab.GUI_WIDGETS_PARENT_ID as the parent id. The class needs a static getInstance() that returns the object holding the current values. The perspective calls it, builds the widgets, and saves through the widget listener.

DatabasePerspectiveConfigPlugin is one box, group "SQL", groupType = BOXES: the auto-connect checkbox, the select-executed-SQL checkbox, and the query row limit. Metadata and configuration covers the command-line side of a configuration plugin.

A TableView, a preview, or a painter does not fit a @GuiWidgetElement field. Register it as an extra group before the widgets are created, and build it into the composite the callback receives. That composite is the same one the annotated fields of that group are on, inside the tab or the box, so a FormAttachment to one of those fields is valid. A table that should fill the group sets its bottom attachment to 100 percent.

The beforeCreate argument exists because addScrolledComposite creates the fields before it returns. registerExtraGroup after that call is too late. The first argument is the group title, the second is the groupOrder, and the third is an optional image (tab icon). Pass null for the image when the group is a box.

ActionDbtDialog puts two name/value tables in an extra group. NamingSchemeEditor puts its preview there. AiProviderEditor puts the per-role model table there.

setWidgetsContents(source, parent, parentId) copies the object into the widgets. getWidgetsContents(source, parentId) copies the widgets back. getWidgetsMap() is the control for each id. getLabelsMap() is the label. getActionWidgetsMap() is the extra control on the right of a field, today the browse button of a FILENAME or FOLDER.

Set a listener with setWidgetsListener. GuiCompositeWidgetsAdapter implements the four methods as no-ops, so a dialog overrides only what it needs:

There is one listener slot. An editor that needs the callback for its own change tracking, and a plugin object that also implements IGuiPluginCompositeWidgetsListener, has to forward the calls. VariableResolverEditor does this.

setWidgetsHidden(source, hiddenIds) hides the named widgets and closes the gap they would leave. Call it from widgetModified when an option only applies to some settings. Hiding a field in one tab or one box does not move the fields in another. Vault resolvers use it to show only the credentials of the selected authentication type.