--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dwtx/jface/preference/ScaleFieldEditor.d	Sat Apr 05 01:45:47 2008 +0200
@@ -0,0 +1,386 @@
+/*******************************************************************************
+ * Copyright (c) 2003, 2006 IBM Corporation and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     IBM Corporation - initial API and implementation
+ * Port to the D programming language:
+ *     Frank Benoit <benoit@tionex.de>
+ *******************************************************************************/
+module dwtx.jface.preference.ScaleFieldEditor;
+
+import dwtx.jface.preference.FieldEditor;
+
+import dwt.DWT;
+import dwt.events.DisposeEvent;
+import dwt.events.DisposeListener;
+import dwt.events.SelectionAdapter;
+import dwt.events.SelectionEvent;
+import dwt.layout.GridData;
+import dwt.widgets.Composite;
+import dwt.widgets.Control;
+import dwt.widgets.Scale;
+
+import dwt.dwthelper.utils;
+
+/**
+ * A field editor for an integer type preference. This class may be used as is,
+ * or subclassed as required.
+ *
+ * @since 3.0
+ */
+public class ScaleFieldEditor : FieldEditor {
+
+    /**
+     * Value that will feed Scale.setIncrement(int).
+     */
+    private int incrementValue;
+
+    /**
+     * Value that will feed Scale.setMaximum(int).
+     */
+    private int maxValue;
+
+    /**
+     * Value that will feed Scale.setMinimum(int).
+     */
+    private int minValue;
+
+    /**
+     * Old integer value.
+     */
+    private int oldValue;
+
+    /**
+     * Value that will feed Scale.setPageIncrement(int).
+     */
+    private int pageIncrementValue;
+
+    /**
+     * The scale, or <code>null</code> if none.
+     */
+    protected Scale scale;
+
+    /**
+     * Creates a scale field editor.
+     *
+     * @param name
+     *            the name of the preference this field editor works on
+     * @param labelText
+     *            the label text of the field editor
+     * @param parent
+     *            the parent of the field editor's control
+     */
+    public this(String name, String labelText, Composite parent) {
+        super(name, labelText, parent);
+        setDefaultValues();
+    }
+
+    /**
+     * Creates a scale field editor with particular scale values.
+     *
+     * @param name
+     *            the name of the preference this field editor works on
+     * @param labelText
+     *            the label text of the field editor
+     * @param parent
+     *            the parent of the field editor's control
+     * @param min
+     *            the value used for Scale.setMinimum(int).
+     * @param max
+     *            the value used for Scale.setMaximum(int).
+     * @param increment
+     *            the value used for Scale.setIncrement(int).
+     * @param pageIncrement
+     *            the value used for Scale.setPageIncrement(int).
+     */
+    public this(String name, String labelText, Composite parent,
+            int min, int max, int increment, int pageIncrement) {
+        super(name, labelText, parent);
+        setValues(min, max, increment, pageIncrement);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see dwtx.jface.preference.FieldEditor#adjustForNumColumns(int)
+     */
+    protected void adjustForNumColumns(int numColumns) {
+        (cast(GridData) scale.getLayoutData()).horizontalSpan = numColumns - 1;
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see dwtx.jface.preference.FieldEditor#doFillIntoGrid(dwt.widgets.Composite,
+     *      int)
+     */
+    protected void doFillIntoGrid(Composite parent, int numColumns) {
+        Control control = getLabelControl(parent);
+        GridData gd = new GridData();
+        control.setLayoutData(gd);
+
+        scale = getScaleControl(parent);
+        gd = new GridData(GridData.FILL_HORIZONTAL);
+        gd.verticalAlignment = GridData.FILL;
+        gd.horizontalSpan = numColumns - 1;
+        gd.grabExcessHorizontalSpace = true;
+        scale.setLayoutData(gd);
+        updateScale();
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see dwtx.jface.preference.FieldEditor#doLoad()
+     */
+    protected void doLoad() {
+        if (scale !is null) {
+            int value = getPreferenceStore().getInt(getPreferenceName());
+            scale.setSelection(value);
+            oldValue = value;
+        }
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see dwtx.jface.preference.FieldEditor#doLoadDefault()
+     */
+    protected void doLoadDefault() {
+        if (scale !is null) {
+            int value = getPreferenceStore().getDefaultInt(getPreferenceName());
+            scale.setSelection(value);
+        }
+        valueChanged();
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see dwtx.jface.preference.FieldEditor#doStore()
+     */
+    protected void doStore() {
+        getPreferenceStore()
+                .setValue(getPreferenceName(), scale.getSelection());
+    }
+
+    /**
+     * Returns the value that will be used for Scale.setIncrement(int).
+     *
+     * @return the value.
+     * @see dwt.widgets.Scale#setIncrement(int)
+     */
+    public int getIncrement() {
+        return incrementValue;
+    }
+
+    /**
+     * Returns the value that will be used for Scale.setMaximum(int).
+     *
+     * @return the value.
+     * @see dwt.widgets.Scale#setMaximum(int)
+     */
+    public int getMaximum() {
+        return maxValue;
+    }
+
+    /**
+     * Returns the value that will be used for Scale.setMinimum(int).
+     *
+     * @return the value.
+     * @see dwt.widgets.Scale#setMinimum(int)
+     */
+    public int getMinimum() {
+        return minValue;
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see dwtx.jface.preference.FieldEditor#getNumberOfControls()
+     */
+    public int getNumberOfControls() {
+        return 2;
+    }
+
+    /**
+     * Returns the value that will be used for Scale.setPageIncrement(int).
+     *
+     * @return the value.
+     * @see dwt.widgets.Scale#setPageIncrement(int)
+     */
+    public int getPageIncrement() {
+        return pageIncrementValue;
+    }
+
+    /**
+     * Returns this field editor's scale control.
+     *
+     * @return the scale control, or <code>null</code> if no scale field is
+     *         created yet
+     */
+    public Scale getScaleControl() {
+        return scale;
+    }
+
+    /**
+     * Returns this field editor's scale control. The control is created if it
+     * does not yet exist.
+     *
+     * @param parent
+     *            the parent
+     * @return the scale control
+     */
+    private Scale getScaleControl(Composite parent) {
+        if (scale is null) {
+            scale = new Scale(parent, DWT.HORIZONTAL);
+            scale.setFont(parent.getFont());
+            scale.addSelectionListener(new class SelectionAdapter {
+                public void widgetSelected(SelectionEvent event) {
+                    valueChanged();
+                }
+            });
+            scale.addDisposeListener(new class DisposeListener {
+                public void widgetDisposed(DisposeEvent event) {
+                    scale = null;
+                }
+            });
+        } else {
+            checkParent(scale, parent);
+        }
+        return scale;
+    }
+
+    /**
+     * Set default values for the various scale fields.  These defaults are:<br>
+     * <ul>
+     * <li>Minimum  = 0
+     * <li>Maximim = 10
+     * <li>Increment = 1
+     * <li>Page Increment = 1
+     * </ul>
+     */
+    private void setDefaultValues() {
+        setValues(0, 10, 1, 1);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see dwtx.jface.preference.FieldEditor#setFocus()
+     */
+    public void setFocus() {
+        if (scale !is null && !scale.isDisposed()) {
+            scale.setFocus();
+        }
+    }
+
+    /**
+     * Set the value to be used for Scale.setIncrement(int) and update the
+     * scale.
+     *
+     * @param increment
+     *            a value greater than 0.
+     * @see dwt.widgets.Scale#setIncrement(int)
+     */
+    public void setIncrement(int increment) {
+        this.incrementValue = increment;
+        updateScale();
+    }
+
+    /**
+     * Set the value to be used for Scale.setMaximum(int) and update the
+     * scale.
+     *
+     * @param max
+     *            a value greater than 0.
+     * @see dwt.widgets.Scale#setMaximum(int)
+     */
+    public void setMaximum(int max) {
+        this.maxValue = max;
+        updateScale();
+    }
+
+    /**
+     * Set the value to be used for Scale.setMinumum(int) and update the
+     * scale.
+     *
+     * @param min
+     *            a value greater than 0.
+     * @see dwt.widgets.Scale#setMinimum(int)
+     */
+    public void setMinimum(int min) {
+        this.minValue = min;
+        updateScale();
+    }
+
+    /**
+     * Set the value to be used for Scale.setPageIncrement(int) and update the
+     * scale.
+     *
+     * @param pageIncrement
+     *            a value greater than 0.
+     * @see dwt.widgets.Scale#setPageIncrement(int)
+     */
+    public void setPageIncrement(int pageIncrement) {
+        this.pageIncrementValue = pageIncrement;
+        updateScale();
+    }
+
+    /**
+     * Set all Scale values.
+     *
+     * @param min
+     *            the value used for Scale.setMinimum(int).
+     * @param max
+     *            the value used for Scale.setMaximum(int).
+     * @param increment
+     *            the value used for Scale.setIncrement(int).
+     * @param pageIncrement
+     *            the value used for Scale.setPageIncrement(int).
+     */
+    private void setValues(int min, int max, int increment, int pageIncrement) {
+        this.incrementValue = increment;
+        this.maxValue = max;
+        this.minValue = min;
+        this.pageIncrementValue = pageIncrement;
+        updateScale();
+    }
+
+    /**
+     * Update the scale particulars with set values.
+     */
+    private void updateScale() {
+        if (scale !is null && !scale.isDisposed()) {
+            scale.setMinimum(getMinimum());
+            scale.setMaximum(getMaximum());
+            scale.setIncrement(getIncrement());
+            scale.setPageIncrement(getPageIncrement());
+        }
+    }
+
+    /**
+     * Informs this field editor's listener, if it has one, about a change to
+     * the value (<code>VALUE</code> property) provided that the old and new
+     * values are different.
+     * <p>
+     * This hook is <em>not</em> called when the scale is initialized (or
+     * reset to the default value) from the preference store.
+     * </p>
+     */
+    protected void valueChanged() {
+        setPresentsDefaultValue(false);
+
+        int newValue = scale.getSelection();
+        if (newValue !is oldValue) {
+            fireStateChanged(IS_VALID, false, true);
+            fireValueChanged(VALUE, new ValueWrapperInt(oldValue),
+                    new ValueWrapperInt(newValue));
+            oldValue = newValue;
+        }
+    }
+}