--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dwt/graphics/Transform.d	Mon Jan 07 09:39:59 2008 +0100
@@ -0,0 +1,366 @@
+/*******************************************************************************
+ * Copyright (c) 2000, 2007 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
+ *******************************************************************************/
+module dwt.graphics.Transform;
+
+import dwt.SWT;
+import dwt.internal.Compatibility;
+import dwt.internal.cairo.Cairo;
+import dwt.internal.gtk.c.cairotypes;
+import dwt.graphics.Resource;
+import dwt.graphics.Device;
+
+import tango.text.convert.Format;
+
+/**
+ * Instances of this class represent transformation matrices for
+ * points expressed as (x, y) pairs of floating point numbers.
+ * <p>
+ * Application code must explicitly invoke the <code>Transform.dispose()</code>
+ * method to release the operating system resources managed by each instance
+ * when those instances are no longer required.
+ * </p>
+ * <p>
+ * This class requires the operating system's advanced graphics subsystem
+ * which may not be available on some platforms.
+ * </p>
+ *
+ * @since 3.1
+ */
+public class Transform : Resource {
+	/**
+	 * the OS resource for the Transform
+	 * (Warning: This field is platform dependent)
+	 * <p>
+	 * <b>IMPORTANT:</b> This field is <em>not</em> part of the SWT
+	 * public API. It is marked public only so that it can be shared
+	 * within the packages provided by SWT. It is not available on all
+	 * platforms and should never be accessed from application code.
+	 * </p>
+	 */
+	public double[] handle;
+
+/**
+ * Constructs a new identity Transform.
+ * <p>
+ * This operation requires the operating system's advanced
+ * graphics subsystem which may not be available on some
+ * platforms.
+ * </p>
+ *
+ * @param device the device on which to allocate the Transform
+ *
+ * @exception IllegalArgumentException <ul>
+ *    <li>ERROR_NULL_ARGUMENT - if device is null and there is no current device</li>
+ * </ul>
+ * @exception SWTException <ul>
+ *    <li>ERROR_NO_GRAPHICS_LIBRARY - if advanced graphics are not available</li>
+ * </ul>
+ * @exception SWTError <ul>
+ *    <li>ERROR_NO_HANDLES if a handle for the Transform could not be obtained</li>
+ * </ul>
+ *
+ * @see #dispose()
+ */
+public this (Device device) {
+	this(device, 1, 0, 0, 1, 0, 0);
+}
+
+/**
+ * Constructs a new Transform given an array of elements that represent the
+ * matrix that describes the transformation.
+ * <p>
+ * This operation requires the operating system's advanced
+ * graphics subsystem which may not be available on some
+ * platforms.
+ * </p>
+ *
+ * @param device the device on which to allocate the Transform
+ * @param elements an array of floats that describe the transformation matrix
+ *
+ * @exception IllegalArgumentException <ul>
+ *    <li>ERROR_NULL_ARGUMENT - if device is null and there is no current device, or the elements array is null</li>
+ *    <li>ERROR_INVALID_ARGUMENT - if the elements array is too small to hold the matrix values</li>
+ * </ul>
+ * @exception SWTException <ul>
+ *    <li>ERROR_NO_GRAPHICS_LIBRARY - if advanced graphics are not available</li>
+ * </ul>
+ * @exception SWTError <ul>
+ *    <li>ERROR_NO_HANDLES if a handle for the Transform could not be obtained</li>
+ * </ul>
+ *
+ * @see #dispose()
+ */
+public this(Device device, float[] elements) {
+	this (device, checkTransform(elements)[0], elements[1], elements[2], elements[3], elements[4], elements[5]);
+}
+
+/**
+ * Constructs a new Transform given all of the elements that represent the
+ * matrix that describes the transformation.
+ * <p>
+ * This operation requires the operating system's advanced
+ * graphics subsystem which may not be available on some
+ * platforms.
+ * </p>
+ *
+ * @param device the device on which to allocate the Transform
+ * @param m11 the first element of the first row of the matrix
+ * @param m12 the second element of the first row of the matrix
+ * @param m21 the first element of the second row of the matrix
+ * @param m22 the second element of the second row of the matrix
+ * @param dx the third element of the first row of the matrix
+ * @param dy the third element of the second row of the matrix
+ *
+ * @exception IllegalArgumentException <ul>
+ *    <li>ERROR_NULL_ARGUMENT - if device is null and there is no current device</li>
+ * </ul>
+ * @exception SWTException <ul>
+ *    <li>ERROR_NO_GRAPHICS_LIBRARY - if advanced graphics are not available</li>
+ * </ul>
+ * @exception SWTError <ul>
+ *    <li>ERROR_NO_HANDLES if a handle for the Transform could not be obtained</li>
+ * </ul>
+ *
+ * @see #dispose()
+ */
+public this (Device device, float m11, float m12, float m21, float m22, float dx, float dy) {
+	if (device is null) device = Device.getDevice();
+	if (device is null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
+	this.device = device;
+	device.checkCairo();
+	handle = new double[6];
+	if (handle is null) SWT.error(SWT.ERROR_NO_HANDLES);
+	Cairo.cairo_matrix_init( cast(cairo_matrix_t*)handle.ptr, m11, m12, m21, m22, dx, dy);
+	if (device.tracking) device.new_Object(this);
+}
+
+static float[] checkTransform(float[] elements) {
+	if (elements == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
+	if (elements.length < 6) SWT.error(SWT.ERROR_INVALID_ARGUMENT);
+	return elements;
+}
+
+/**
+ * Disposes of the operating system resources associated with
+ * the Transform. Applications must dispose of all Transforms that
+ * they allocate.
+ */
+public void dispose() {
+	if (handle is null) return;
+	if (device.isDisposed()) return;
+	handle = null;
+	if (device.tracking) device.dispose_Object(this);
+	device = null;
+}
+
+/**
+ * Fills the parameter with the values of the transformation matrix
+ * that the receiver represents, in the order {m11, m12, m21, m22, dx, dy}.
+ *
+ * @param elements array to hold the matrix values
+ *
+ * @exception SWTException <ul>
+ *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
+ * </ul>
+ * @exception IllegalArgumentException <ul>
+ *    <li>ERROR_NULL_ARGUMENT - if the parameter is null</li>
+ *    <li>ERROR_INVALID_ARGUMENT - if the parameter is too small to hold the matrix values</li>
+ * </ul>
+ */
+public void getElements(float[] elements) {
+	if (isDisposed()) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
+	if (elements is null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
+	if (elements.length < 6) SWT.error(SWT.ERROR_INVALID_ARGUMENT);
+	elements[0] = cast(float)handle[0];
+	elements[1] = cast(float)handle[1];
+	elements[2] = cast(float)handle[2];
+	elements[3] = cast(float)handle[3];
+	elements[4] = cast(float)handle[4];
+	elements[5] = cast(float)handle[5];
+}
+
+/**
+ * Modifies the receiver such that the matrix it represents becomes the
+ * the mathematical inverse of the matrix it previously represented.
+ *
+ * @exception SWTException <ul>
+ *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
+ *    <li>ERROR_CANNOT_INVERT_MATRIX - if the matrix is not invertible</li>
+ * </ul>
+ */
+public void invert() {
+	if (isDisposed()) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
+	if (Cairo.cairo_matrix_invert(cast(cairo_matrix_t*)handle.ptr) != 0) {
+		SWT.error(SWT.ERROR_CANNOT_INVERT_MATRIX);
+	}
+}
+
+/**
+ * Returns <code>true</code> if the Transform has been disposed,
+ * and <code>false</code> otherwise.
+ * <p>
+ * This method gets the dispose state for the Transform.
+ * When a Transform has been disposed, it is an error to
+ * invoke any other method using the Transform.
+ *
+ * @return <code>true</code> when the Transform is disposed, and <code>false</code> otherwise
+ */
+public bool isDisposed() {
+	return handle is null;
+}
+
+/**
+ * Returns <code>true</code> if the Transform represents the identity matrix
+ * and false otherwise.
+ *
+ * @return <code>true</code> if the receiver is an identity Transform, and <code>false</code> otherwise
+ */
+public bool isIdentity() {
+	if (isDisposed()) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
+	float[] m  = new float[6];
+	getElements(m);
+	return m[0] == 1 && m[1] == 0 && m[2] == 0 && m[3] == 1 && m[4] == 0 && m[5] == 0;
+}
+
+/**
+ * Modifies the receiver such that the matrix it represents becomes the
+ * the result of multiplying the matrix it previously represented by the
+ * argument.
+ *
+ * @param matrix the matrix to multiply the receiver by
+ *
+ * @exception SWTException <ul>
+ *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
+ * </ul>
+ * @exception IllegalArgumentException <ul>
+ *    <li>ERROR_NULL_ARGUMENT - if the parameter is null</li>
+ *    <li>ERROR_INVALID_ARGUMENT - if the parameter has been disposed</li>
+ * </ul>
+ */
+public void multiply(Transform matrix) {
+	if (isDisposed()) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
+	if (matrix == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
+	if (matrix.isDisposed()) SWT.error(SWT.ERROR_INVALID_ARGUMENT);
+	Cairo.cairo_matrix_multiply(cast(cairo_matrix_t*)handle.ptr,cast(cairo_matrix_t*)matrix.handle.ptr, cast(cairo_matrix_t*)handle.ptr);
+}
+
+/**
+ * Modifies the receiver so that it represents a transformation that is
+ * equivalent to its previous transformation rotated by the specified angle.
+ * The angle is specified in degrees and for the identity transform 0 degrees
+ * is at the 3 o'clock position. A positive value indicates a clockwise rotation
+ * while a negative value indicates a counter-clockwise rotation.
+ *
+ * @param angle the angle to rotate the transformation by
+ *
+ * @exception SWTException <ul>
+ *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
+ * </ul>
+ */
+public void rotate(float angle) {
+	if (isDisposed()) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
+	Cairo.cairo_matrix_rotate(cast(cairo_matrix_t*)handle.ptr, angle * cast(float)Compatibility.PI / 180);
+}
+
+/**
+ * Modifies the receiver so that it represents a transformation that is
+ * equivalent to its previous transformation scaled by (scaleX, scaleY).
+ *
+ * @param scaleX the amount to scale in the X direction
+ * @param scaleY the amount to scale in the Y direction
+ *
+ * @exception SWTException <ul>
+ *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
+ * </ul>
+ */
+public void scale(float scaleX, float scaleY) {
+	if (isDisposed()) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
+	Cairo.cairo_matrix_scale(cast(cairo_matrix_t*)handle.ptr, scaleX, scaleY);
+}
+
+/**
+ * Modifies the receiver to represent a new transformation given all of
+ * the elements that represent the matrix that describes that transformation.
+ *
+ * @param m11 the first element of the first row of the matrix
+ * @param m12 the second element of the first row of the matrix
+ * @param m21 the first element of the second row of the matrix
+ * @param m22 the second element of the second row of the matrix
+ * @param dx the third element of the first row of the matrix
+ * @param dy the third element of the second row of the matrix
+ *
+ * @exception SWTException <ul>
+ *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
+ * </ul>
+ */
+public void setElements(float m11, float m12, float m21, float m22, float dx, float dy) {
+	if (isDisposed()) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
+	Cairo.cairo_matrix_init(cast(cairo_matrix_t*)handle.ptr, m11, m12, m21, m22, dx, dy);
+}
+
+/**
+ * Given an array containing points described by alternating x and y values,
+ * modify that array such that each point has been replaced with the result of
+ * applying the transformation represented by the receiver to that point.
+ *
+ * @param pointArray an array of alternating x and y values to be transformed
+ *
+ * @exception IllegalArgumentException <ul>
+ *    <li>ERROR_NULL_ARGUMENT - if the point array is null</li>
+ * </ul>
+ * @exception SWTException <ul>
+ *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
+ * </ul>
+ */
+public void transform(float[] pointArray) {
+	if (isDisposed()) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
+	if (pointArray == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
+	double dx, dy;
+	int length = pointArray.length / 2;
+	for (int i = 0, j = 0; i < length; i++, j += 2) {
+		dx = pointArray[j];
+		dy = pointArray[j + 1];
+		Cairo.cairo_matrix_transform_point(cast(cairo_matrix_t*)handle.ptr, &dx, &dy);
+		pointArray[j] = cast(float)dx;
+		pointArray[j + 1] = cast(float)dy;
+	}
+}
+
+/**
+ * Modifies the receiver so that it represents a transformation that is
+ * equivalent to its previous transformation translated by (offsetX, offsetY).
+ *
+ * @param offsetX the distance to translate in the X direction
+ * @param offsetY the distance to translate in the Y direction
+ *
+ * @exception SWTException <ul>
+ *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
+ * </ul>
+ */
+public void translate(float offsetX, float offsetY) {
+	if (isDisposed()) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
+	Cairo.cairo_matrix_translate(cast(cairo_matrix_t*)handle.ptr, offsetX, offsetY);
+}
+
+/**
+ * Returns a string containing a concise, human-readable
+ * description of the receiver.
+ *
+ * @return a string representation of the receiver
+ */
+public char[] toString() {
+	if (isDisposed()) return "Transform {*DISPOSED*}";
+	float[] elements = new float[6];
+	getElements(elements);
+	return Format( "Transform {{{}}", elements );
+}
+
+}

--- a/todo.txt	Mon Jan 07 09:25:10 2008 +0100
+++ b/todo.txt	Mon Jan 07 09:39:59 2008 +0100
@@ -53,7 +53,7 @@
 graphics/RGB                           // OK
 graphics/TextLayout
 graphics/TextStyle                     // OK
-graphics/Transform
+graphics/Transform                     // OK
 
 widgets/TableColumn
 widgets/DirectoryDialog