/**
* Constructs a new Pattern that can be used to draw an SVG style radial gradient. Before using
* the pattern, at least two color stops must be added.
*
* <p>This operation requires the operating system's advanced graphics subsystem which may not be
* available on some platforms.
*
* @param device the device on which to allocate the pattern
* @param cx the x coordinate of the center of the largest (i.e., outermost) circle for the radial
* gradient. The gradient will be drawn such that the 100% gradient stop is mapped to the
* perimeter of this largest (i.e., outermost) circle.
* @param cy the y coordinate of the center of the largest (i.e., outermost) circle
* @param fx the x coordinate of the focal point for the radial gradient. The gradient will be
* drawn such that the 0% gradient stop is mapped to (fx, fy).
* @param fy the y coordinate of the focal point
* @param r the radius of the largest (i.e., outermost) circle
* @exception SWTException
* <ul>
* <li>ERROR_NO_GRAPHICS_LIBRARY - if advanced graphics are not available
* </ul>
*
* @see #addStop(Color, float)
* @see #addStop(Color, float, int)
* @since ???
*/
public Pattern(Device device, float cx, float cy, float fx, float fy, float r) {
super(device);
this.device.checkCairo();
handle = Cairo.cairo_pattern_create_radial(fx, fy, 0, cx, cy, r);
Cairo.cairo_pattern_set_extend(handle, Cairo.CAIRO_EXTEND_PAD);
init();
}
/**
* Constructs a new Pattern that can be used to draw an SVG style linear gradient. Before using
* the pattern, at least two color stops must be added.
*
* <p>This operation requires the operating system's advanced graphics subsystem which may not be
* available on some platforms.
*
* @param device the device on which to allocate the pattern
* @param x1 the x coordinate of the starting corner of the gradient
* @param y1 the y coordinate of the starting corner of the gradient
* @param x2 the x coordinate of the ending corner of the gradient
* @param y2 the y coordinate of the ending corner of the gradient
* @exception SWTException
* <ul>
* <li>ERROR_NO_GRAPHICS_LIBRARY - if advanced graphics are not available
* </ul>
*
* @see #addStop(Color, float)
* @see #addStop(Color, float, int)
* @since ???
*/
public Pattern(Device device, float x1, float y1, float x2, float y2) {
super(device);
this.device.checkCairo();
handle = Cairo.cairo_pattern_create_linear(x1, y1, x2, y2);
Cairo.cairo_pattern_set_extend(handle, Cairo.CAIRO_EXTEND_PAD);
init();
}
/**
* Constructs a new Pattern given an image. Drawing with the resulting pattern will cause the
* image to be tiled over the resulting area.
*
* <p>This operation requires the operating system's advanced graphics subsystem which may not be
* available on some platforms.
*
* @param device the device on which to allocate the pattern
* @param image the image that the pattern will draw
* @exception IllegalArgumentException
* <ul>
* <li>ERROR_NULL_ARGUMENT - if the device is null and there is no current device, or the
* image is null
* <li>ERROR_INVALID_ARGUMENT - if the image has been disposed
* </ul>
*
* @exception SWTException
* <ul>
* <li>ERROR_NO_GRAPHICS_LIBRARY - if advanced graphics are not available
* </ul>
*
* @exception SWTError
* <ul>
* <li>ERROR_NO_HANDLES if a handle for the pattern could not be obtained
* </ul>
*
* @see #dispose()
*/
public Pattern(Device device, Image image) {
super(device);
if (image == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
if (image.isDisposed()) SWT.error(SWT.ERROR_INVALID_ARGUMENT);
this.device.checkCairo();
image.createSurface();
handle = Cairo.cairo_pattern_create_for_surface(image.surface);
if (handle == 0) SWT.error(SWT.ERROR_NO_HANDLES);
Cairo.cairo_pattern_set_extend(handle, Cairo.CAIRO_EXTEND_REPEAT);
surface = image.surface;
init();
}
/**
* Constructs a new Pattern that represents a linear, two color gradient. Drawing with the pattern
* will cause the resulting area to be tiled with the gradient specified by the arguments.
*
* <p>This operation requires the operating system's advanced graphics subsystem which may not be
* available on some platforms.
*
* @param device the device on which to allocate the pattern
* @param x1 the x coordinate of the starting corner of the gradient
* @param y1 the y coordinate of the starting corner of the gradient
* @param x2 the x coordinate of the ending corner of the gradient
* @param y2 the y coordinate of the ending corner of the gradient
* @param color1 the starting color of the gradient
* @param alpha1 the starting alpha value of the gradient
* @param color2 the ending color of the gradient
* @param alpha2 the ending alpha value of the gradient
* @exception IllegalArgumentException
* <ul>
* <li>ERROR_NULL_ARGUMENT - if the device is null and there is no current device, or if
* either color1 or color2 is null
* <li>ERROR_INVALID_ARGUMENT - if either color1 or color2 has been disposed
* </ul>
*
* @exception SWTException
* <ul>
* <li>ERROR_NO_GRAPHICS_LIBRARY - if advanced graphics are not available
* </ul>
*
* @exception SWTError
* <ul>
* <li>ERROR_NO_HANDLES if a handle for the pattern could not be obtained
* </ul>
*
* @see #dispose()
* @since 3.2
*/
public Pattern(
Device device,
float x1,
float y1,
float x2,
float y2,
Color color1,
int alpha1,
Color color2,
int alpha2) {
super(device);
if (color1 == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
if (color1.isDisposed()) SWT.error(SWT.ERROR_INVALID_ARGUMENT);
if (color2 == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
if (color2.isDisposed()) SWT.error(SWT.ERROR_INVALID_ARGUMENT);
this.device.checkCairo();
handle = Cairo.cairo_pattern_create_linear(x1, y1, x2, y2);
if (handle == 0) SWT.error(SWT.ERROR_NO_HANDLES);
GC.setCairoPatternColor(handle, 0, color1, alpha1);
GC.setCairoPatternColor(handle, 1, color2, alpha2);
Cairo.cairo_pattern_set_extend(handle, Cairo.CAIRO_EXTEND_REPEAT);
init();
}
/**
* Indicates what happens if the gradient starts or ends inside the bounds of the object(s) being
* painted by the gradient.
*
* <p>Possible values are: 'pad', which says to use the terminal colors of the gradient to fill
* the remainder of the target region, 'reflect', which says to reflect the gradient pattern
* start-to-end, end-to-start, start-to-end, etc. continuously until the target rectangle is
* filled, and repeat, which says to repeat the gradient pattern start-to-end, start-to-end,
* start-to-end, etc. continuously until the target region is filled. If the attribute is not
* specified, the effect is as if a value of 'pad' were specified.
*
* @see #PAD
* @see #REFLECT
* @see #REPEAT
*/
public void setSpreadMethod(int method) {
if (method != PAD && method != REFLECT && method != REPEAT) {
SWT.error(SWT.ERROR_INVALID_ARGUMENT);
}
Cairo.cairo_pattern_set_extend(handle, method);
}
void destroy() {
Cairo.cairo_pattern_destroy(handle);
handle = surface = 0;
}
