r/org.eclipse.statet.r.ui/src/org/eclipse/statet/internal/r/ui/datafilterview/FilterClient.java

/*=============================================================================#
 # Copyright (c) 2012, 2021 Stephan Wahlbrink and others.
 # 
 # This program and the accompanying materials are made available under the
 # terms of the Eclipse Public License 2.0 which is available at
 # https://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
 # which is available at https://www.apache.org/licenses/LICENSE-2.0.
 # 
 # SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
 # 
 # Contributors:
 #     Stephan Wahlbrink <sw@wahlbrink.eu> - initial API and implementation
 #=============================================================================*/

package org.eclipse.statet.internal.r.ui.datafilterview;

import static org.eclipse.statet.jcommons.lang.ObjectUtils.nonNullAssert;
import static org.eclipse.statet.jcommons.lang.ObjectUtils.nonNullLateInit;

import org.eclipse.jface.dialogs.MessageLine;
import org.eclipse.jface.viewers.TableViewer;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.DisposeEvent;
import org.eclipse.swt.events.DisposeListener;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Listener;
import org.eclipse.ui.IWorkbenchCommandConstants;
import org.eclipse.ui.services.IServiceLocator;

import org.eclipse.statet.jcommons.lang.NonNull;
import org.eclipse.statet.jcommons.lang.NonNullByDefault;
import org.eclipse.statet.jcommons.lang.Nullable;

import org.eclipse.statet.ecommons.databinding.jface.DataBindingSupport;
import org.eclipse.statet.ecommons.ui.util.LayoutUtils;

import org.eclipse.statet.internal.r.ui.datafilter.VariableFilter;


@NonNullByDefault
public abstract class FilterClient<TFilter extends VariableFilter> extends Composite {
	
	
	protected static final String SELECT_ALL_COMMAND_ID= IWorkbenchCommandConstants.EDIT_SELECT_ALL;
	protected static final String REMOVE_COMMAND_ID= IWorkbenchCommandConstants.EDIT_DELETE;
	protected static final String REMOVE_ALL_HANDLER_COMMAND_ID= "RemoveAll"; //$NON-NLS-1$
	protected static final String REMOVE_UNCHECKED_HANDLER_ID= "RemoveUnchecked"; //$NON-NLS-1$
	
	
	protected final TFilter filter;
	
	private DataBindingSupport dataBinding= nonNullLateInit();
	
	private @Nullable Listener resizeListener;
	
	private @Nullable MessageLine statusInfo;
	private boolean layoutChanged;
	
	
	public FilterClient(final VariableComposite parent, final TFilter filter) {
		super(parent, SWT.NONE);
		
		this.filter= filter;
		filter.setListener(this::onFilterDataChanged);
		
		addDisposeListener(new DisposeListener() {
			@Override
			public void widgetDisposed(final DisposeEvent e) {
				onDispose();
			}
		});
	}
	
	
	@Override
	@SuppressWarnings("null")
	public VariableComposite getParent() {
		return (VariableComposite)super.getParent();
	}
	
	public abstract VariableFilter getFilter();
	
	protected void init(final int numColumns) {
		getParent().setClient(this);
		
		setLayout(LayoutUtils.newCompositeGrid(numColumns));
		
		addWidgets();
		LayoutUtils.addSmallFiller(this, false);
		initActions(getParent().getContainer().getServiceLocator());
		initBindings();
		onFilterDataChanged();
	}
	
	@SuppressWarnings("null")
	protected int getNumColumns() {
		return ((GridLayout)getLayout()).numColumns;
	}
	
	protected void addStatusInfoLine() {
		final var statusInfo= new MessageLine(this, SWT.NONE);
		statusInfo.setLayoutData(new GridData(SWT.FILL, SWT.CENTER, true, false,
				getNumColumns(), 1) );
		this.statusInfo= statusInfo;
		updateStatusInfo();
	}
	
	
	protected abstract void addWidgets();
	
	protected abstract void initActions(IServiceLocator serviceLocator);
	
	protected void onFilterDataChanged() {
		if (isDisposed()) {
			return;
		}
		updateStatusInfo();
		updateInput();
		this.dataBinding.getContext().updateTargets();
	}
	
	protected void updateStatusInfo() {
		final var statusInfo= this.statusInfo;
		if (statusInfo != null) {
			final var status= getFilter().getStatus();
			statusInfo.setErrorStatus(status);
			final var layoutData= nonNullAssert((GridData)statusInfo.getLayoutData());
			final boolean show= (status != null);
			if (show != statusInfo.isVisible()) {
				statusInfo.setVisible(show);
				layoutData.exclude= !show;
				this.layoutChanged= true;
			}
		}
	}
	
	protected abstract void updateInput();
	
	protected void initBindings() {
		this.dataBinding= new DataBindingSupport(this);
		addBindings(this.dataBinding);
	}
	
	protected void addBindings(final DataBindingSupport db) {
	}
	
	protected DataBindingSupport getDataBinding() {
		return this.dataBinding;
	}
	
	
	protected void installResizeListener() {
		var listener= this.resizeListener;
		if (listener == null) {
			listener= new Listener() {
				@Override
				public void handleEvent(final Event event) {
					checkLayout();
				}
			};
			getParent().getContainer().getComposite().addListener(SWT.Resize, listener);
			this.resizeListener= listener;
		}
	}
	
	protected void checkLayout() {
		if (updateLayout() || this.layoutChanged) {
			getParent().layout(new @NonNull Control[] { this });
		}
	}
	
	protected boolean updateLayout() {
		return false;
	}
	
	protected boolean updateLayout(final TableViewer viewer, final int count) {
		final GridData data= new GridData(SWT.FILL, SWT.CENTER, true, false,
				getNumColumns(), 1 );
		if (count == 0) {
			data.exclude= true;
		}
		else {
			data.heightHint= LayoutUtils.hintHeight(viewer.getTable(), count, false);
			final int max= Math.max(5 * viewer.getTable().getItemHeight(),
					getParent().getContainer().getComposite().getClientArea().height
							- getMinHeightPadding() );
			if (data.heightHint > max) {
				data.heightHint= max;
			}
			installResizeListener();
		}
		
		{	final Control control= viewer.getControl();
			final GridData oldData= ((GridData)control.getLayoutData());
			if (oldData == null || oldData.exclude != data.exclude || oldData.heightHint != data.heightHint) {
				control.setVisible(!data.exclude);
				control.setLayoutData(data);
				return true;
			}
			return false;
		}
	}
	
	protected int getMinHeightPadding() {
		return 20 + 8 * LayoutUtils.defaultVSpacing();
	}
	
	@Override
	public void layout(boolean changed, final boolean all) {
		changed |= updateLayout();
		super.layout(changed, all);
	}
	
	@Override
	public void layout(final @NonNull Control @Nullable [] changed, int flags) {
		if (updateLayout() || this.layoutChanged) {
			this.layoutChanged= false;
			flags |= SWT.CHANGED;
		}
		super.layout(changed, flags);
	}
	
	
	protected void onDispose() {
		{	final var listener= this.resizeListener;
			if (listener != null) {
				this.resizeListener= null;
				getParent().getContainer().getComposite().removeListener(SWT.Resize, listener);
			}
		}
	}
	
}