From 0e4bb0d5828e5a458188ab921cd4675e28435404 Mon Sep 17 00:00:00 2001
From: Christian Femers <femers@in.tum.de>
Date: Tue, 24 Sep 2019 06:26:39 +0200
Subject: [PATCH] Tool class for creating Combos that allow to select
 machines/projects

---
 .../plugin/nature/MachineContextSwtTools.java | 199 ++++++++++++++++++
 1 file changed, 199 insertions(+)
 create mode 100644 plugins/net.mograsim.plugin.core/src/net/mograsim/plugin/nature/MachineContextSwtTools.java

diff --git a/plugins/net.mograsim.plugin.core/src/net/mograsim/plugin/nature/MachineContextSwtTools.java b/plugins/net.mograsim.plugin.core/src/net/mograsim/plugin/nature/MachineContextSwtTools.java
new file mode 100644
index 00000000..9c0ad0b3
--- /dev/null
+++ b/plugins/net.mograsim.plugin.core/src/net/mograsim/plugin/nature/MachineContextSwtTools.java
@@ -0,0 +1,199 @@
+package net.mograsim.plugin.nature;
+
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Optional;
+import java.util.Set;
+import java.util.function.Consumer;
+import java.util.function.Function;
+
+import org.eclipse.core.resources.IProject;
+import org.eclipse.jface.viewers.ComboViewer;
+import org.eclipse.jface.viewers.IStructuredContentProvider;
+import org.eclipse.jface.viewers.LabelProvider;
+import org.eclipse.jface.viewers.ViewerComparator;
+import org.eclipse.swt.SWT;
+import org.eclipse.swt.widgets.Combo;
+import org.eclipse.swt.widgets.Composite;
+import org.eclipse.swt.widgets.Display;
+
+import net.mograsim.machine.MachineDefinition;
+import net.mograsim.machine.MachineRegistry;
+import net.mograsim.plugin.nature.ProjectContextEvent.ProjectContextEventType;
+
+public final class MachineContextSwtTools
+{
+	private static final Map<String, MachineDefinition> INSTALLED_MACHINES = MachineRegistry.getInstalledMachines();
+	private static final Map<IProject, MachineContext> PROJECT_MACHINE_CONTEXTS = ProjectMachineContext.getAllProjectMachineContexts();
+
+	private MachineContextSwtTools()
+	{
+		// not instantiable
+	}
+
+	public static MachineCombo createMachineSelector(Composite parent, int style)
+	{
+		return new MachineCombo(parent, style);
+	}
+
+	public static MograsimProjectCombo createMograsimProjectSelector(Composite parent, int style)
+	{
+		return new MograsimProjectCombo(parent, style);
+	}
+
+	public abstract static class AdvancedCombo<T>
+	{
+		final ComboViewer combo;
+		private Set<Consumer<T>> listeners;
+
+		public AdvancedCombo(Composite parent, Function<T, String> labelProvider)
+		{
+			this(parent, SWT.NONE, labelProvider);
+		}
+
+		public AdvancedCombo(Composite parent, int style, Function<T, String> labelProvider)
+		{
+			listeners = Collections.synchronizedSet(new HashSet<>());
+			combo = new ComboViewer(parent, style);
+			combo.addSelectionChangedListener(e -> updateSelection());
+			combo.setComparator(new ViewerComparator());
+			combo.setLabelProvider(new LabelProvider()
+			{
+				@SuppressWarnings("unchecked")
+				@Override
+				public String getText(Object element)
+				{
+					try
+					{
+						return labelProvider.apply((T) element);
+					}
+					catch (ClassCastException e)
+					{
+						return "Invalid Element: " + e.getLocalizedMessage();
+					}
+				}
+			});
+		}
+
+		public final ComboViewer getCombo()
+		{
+			return combo;
+		}
+
+		@SuppressWarnings("unchecked")
+		public T getSelection()
+		{
+			return (T) combo.getStructuredSelection().getFirstElement();
+		}
+
+		private void updateSelection()
+		{
+			T active = getSelection();
+			listeners.forEach(l -> l.accept(active));
+		}
+
+		public final void addListener(Consumer<T> listener)
+		{
+			listeners.add(listener);
+		}
+
+		public final void removeListener(Consumer<T> listener)
+		{
+			listeners.remove(listener);
+		}
+
+		public void refreshContent()
+		{
+			Display.getDefault().asyncExec(combo::refresh);
+		}
+	}
+
+	public static class MachineCombo extends AdvancedCombo<MachineDefinition>
+	{
+		private static final Set<MachineCombo> machineComboListeners = Collections.synchronizedSet(new HashSet<>());
+
+		static
+		{
+			MachineRegistry.addMachineRegistryListener(newMap -> machineComboListeners.forEach(AdvancedCombo::refreshContent));
+		}
+
+		public MachineCombo(Composite parent)
+		{
+			this(parent, SWT.NONE);
+		}
+
+		public MachineCombo(Composite parent, int style)
+		{
+			super(parent, style, MachineDefinition::getId);
+			combo.setContentProvider(new IStructuredContentProvider()
+			{
+				@Override
+				public void dispose()
+				{
+					machineComboListeners.remove(MachineCombo.this);
+				}
+
+				@Override
+				public Object[] getElements(Object inputElement)
+				{
+					return INSTALLED_MACHINES.values().toArray();
+				}
+			});
+			combo.setInput(this);
+			machineComboListeners.add(this);
+		}
+	}
+
+	public static class MograsimProjectCombo extends AdvancedCombo<IProject>
+	{
+		private static final Set<MograsimProjectCombo> projectComboListeners = Collections.synchronizedSet(new HashSet<>());
+
+		static
+		{
+			ProjectMachineContext.addProjectContextListener(projectEvent ->
+			{
+				if (projectEvent.getEventType() != ProjectContextEventType.OTHER_CHANGE)
+					projectComboListeners.forEach(AdvancedCombo::refreshContent);
+			});
+		}
+
+		public MograsimProjectCombo(Composite parent)
+		{
+			this(parent, SWT.NONE);
+		}
+
+		public MograsimProjectCombo(Composite parent, int style)
+		{
+			super(parent, style, IProject::getName);
+			combo.setContentProvider(new IStructuredContentProvider()
+			{
+				@Override
+				public void dispose()
+				{
+					projectComboListeners.remove(MograsimProjectCombo.this);
+				}
+
+				@Override
+				public Object[] getElements(Object inputElement)
+				{
+					return PROJECT_MACHINE_CONTEXTS.values().stream().filter(mc -> mc.getProject().isOpen() && mc.isCurrentyValid())
+							.map(MachineContext::getProject).toArray();
+				}
+			});
+			combo.setInput(this);
+			projectComboListeners.add(this);
+		}
+	}
+
+	/**
+	 * XXX: of no use?
+	 */
+	static Optional<String> getSelection(Combo c)
+	{
+		int selectionIndex = c.getSelectionIndex();
+		if (selectionIndex == -1)
+			return Optional.empty();
+		return Optional.of(c.getItem(selectionIndex));
+	}
+}
-- 
2.17.1