Skip to content

[Win32] Lazy load Cursor handles #2362

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 1 commit into from
Sep 6, 2025
Merged

[Win32] Lazy load Cursor handles #2362

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
113 changes: 45 additions & 68 deletions bundles/org.eclipse.swt/Eclipse SWT/win32/org/eclipse/swt/graphics/Cursor.java
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -49,18 +49,6 @@
*/
public final class Cursor extends Resource {

/**
* the handle to the OS cursor resource
* (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>
*
*/
private long handle;
/**
* Attribute to cache current native zoom level
*/
Expand All @@ -70,6 +58,8 @@ public final class Cursor extends Resource {

private final CursorHandleProvider cursorHandleProvider;

private boolean isDestroyed;

/**
* Constructs a new cursor given a device and a style
* constant describing the desired cursor appearance.
Expand Down Expand Up @@ -119,7 +109,6 @@ public final class Cursor extends Resource {
public Cursor(Device device, int style) {
super(device);
this.cursorHandleProvider = new StyleCursorHandleProvider(style);
this.handle = this.cursorHandleProvider.createHandle(this.device, DEFAULT_ZOOM).getHandle();
init();
this.device.registerResourceWithZoomSupport(this);
}
Expand Down Expand Up @@ -160,28 +149,14 @@ public Cursor(Device device, int style) {
public Cursor(Device device, ImageData source, ImageData mask, int hotspotX, int hotspotY) {
super(device);
this.cursorHandleProvider = new ImageDataWithMaskCursorHandleProvider(source, mask, hotspotX, hotspotY);
this.handle = this.cursorHandleProvider.createHandle(this.device, DEFAULT_ZOOM).getHandle();
init();
this.device.registerResourceWithZoomSupport(this);
}

private static CursorHandle setupCursorFromImageData(ImageData source, ImageData mask, int hotspotX, int hotspotY) {
if (source == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
if (mask == null) {
if (source.getTransparencyType() != SWT.TRANSPARENCY_MASK) {
SWT.error(SWT.ERROR_NULL_ARGUMENT);
}
mask = source.getTransparencyMask();
}
/* Check the bounds. Mask must be the same size as source */
if (mask.width != source.width || mask.height != source.height) {
SWT.error(SWT.ERROR_INVALID_ARGUMENT);
}
/* Check the hotspots */
if (hotspotX >= source.width || hotspotX < 0 ||
hotspotY >= source.height || hotspotY < 0) {
SWT.error(SWT.ERROR_INVALID_ARGUMENT);
}
/* Convert depth to 1 */
mask = ImageData.convertMask(mask);
source = ImageData.convertMask(source);
Expand Down Expand Up @@ -229,18 +204,12 @@ private static CursorHandle setupCursorFromImageData(ImageData source, ImageData
public Cursor(Device device, ImageData source, int hotspotX, int hotspotY) {
super(device);
this.cursorHandleProvider = new ImageDataCursorHandleProvider(source, hotspotX, hotspotY);
this.handle = this.cursorHandleProvider.createHandle(this.device, DEFAULT_ZOOM).getHandle();
init();
this.device.registerResourceWithZoomSupport(this);
}

private static CursorHandle setupCursorFromImageData(Device device, ImageData source, int hotspotX, int hotspotY) {
if (source == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
/* Check the hotspots */
if (hotspotX >= source.width || hotspotX < 0 ||
hotspotY >= source.height || hotspotY < 0) {
SWT.error(SWT.ERROR_INVALID_ARGUMENT);
}
long hBitmap = 0;
long hMask = 0;
if (source.maskData == null && source.transparentPixel == -1 && (source.alpha != -1 || source.alphaData != null)) {
Expand Down Expand Up @@ -341,7 +310,6 @@ public Cursor(Device device, ImageDataProvider imageDataProvider, int hotspotX,
super(device);
if (imageDataProvider == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
this.cursorHandleProvider = new ImageDataProviderCursorHandleProvider(imageDataProvider, hotspotX, hotspotY);
this.handle = this.cursorHandleProvider.createHandle(this.device, DEFAULT_ZOOM).getHandle();
init();
this.device.registerResourceWithZoomSupport(this);
}
Expand All @@ -363,7 +331,7 @@ public Cursor(Device device, ImageDataProvider imageDataProvider, int hotspotX,
*/
public static Long win32_getHandle (Cursor cursor, int zoom) {
if (cursor.isDisposed()) {
return cursor.handle;
return 0L;
}
if (cursor.zoomLevelToHandle.get(zoom) != null) {
return cursor.zoomLevelToHandle.get(zoom).getHandle();
Expand All @@ -376,38 +344,19 @@ public static Long win32_getHandle (Cursor cursor, int zoom) {
}

private void setHandleForZoomLevel(CursorHandle handle, Integer zoom) {
if (this.handle == 0) {
this.handle = handle.getHandle(); // Set handle for default zoom level
}
if (zoom != null && !zoomLevelToHandle.containsKey(zoom)) {
zoomLevelToHandle.put(zoom, handle);
}
}

@Override
void destroy () {
/*
* It is an error in Windows to destroy the current
* cursor. Check that the cursor that is about to
* be destroyed is the current cursor. If so, set
* the current cursor to be IDC_ARROW. Note that
* Windows shares predefined cursors so the call to
* LoadCursor() does not leak.
*/
// TEMPORARY CODE
// if (OS.GetCursor() == handle) {
// OS.SetCursor(OS.LoadCursor(0, OS.IDC_ARROW));
// }
device.deregisterResourceWithZoomSupport(this);
destroyHandle();
}

private void destroyHandle () {
for (CursorHandle handle : zoomLevelToHandle.values()) {
handle.destroy();
}
zoomLevelToHandle.clear();
handle = 0;
this.isDestroyed = true;
}

/**
Expand All @@ -425,7 +374,7 @@ public boolean equals (Object object) {
if (object == this) return true;
if (!(object instanceof Cursor)) return false;
Cursor cursor = (Cursor) object;
return device == cursor.device && handle == cursor.handle;
return device == cursor.device && win32_getHandle(this, DEFAULT_ZOOM) == win32_getHandle(cursor, DEFAULT_ZOOM);
}

/**
Expand All @@ -440,7 +389,7 @@ public boolean equals (Object object) {
*/
@Override
public int hashCode () {
return (int)handle;
return win32_getHandle(this, DEFAULT_ZOOM).intValue();
}

/**
Expand All @@ -455,7 +404,7 @@ public int hashCode () {
*/
@Override
public boolean isDisposed() {
return handle == 0;
return isDestroyed;
}

/**
Expand All @@ -467,7 +416,7 @@ public boolean isDisposed() {
@Override
public String toString () {
if (isDisposed()) return "Cursor {*DISPOSED*}";
return "Cursor {" + handle + "}";
return "Cursor {" + zoomLevelToHandle + "}";
}

@Override
Expand Down Expand Up @@ -531,19 +480,23 @@ private static interface CursorHandleProvider {
}

private static class StyleCursorHandleProvider implements CursorHandleProvider {
private final int style;
private final long lpCursorName;

public StyleCursorHandleProvider(int style) {
this.style = style;
this.lpCursorName = getOSCursorIdFromStyle(style);
}

@Override
public CursorHandle createHandle(Device device, int zoom) {
// zoom ignored, LoadCursor handles scaling internally
return setupCursorFromStyle(this.style);
long handle = OS.LoadCursor(0, lpCursorName);
if (handle == 0) {
SWT.error(SWT.ERROR_NO_HANDLES);
}
return new CustomCursorHandle(handle);
}

private static final CursorHandle setupCursorFromStyle(int style) {
private static final long getOSCursorIdFromStyle(int style) {
long lpCursorName = 0;
switch (style) {
case SWT.CURSOR_HAND:
Expand Down Expand Up @@ -615,11 +568,7 @@ private static final CursorHandle setupCursorFromStyle(int style) {
default:
SWT.error(SWT.ERROR_INVALID_ARGUMENT);
}
long handle = OS.LoadCursor(0, lpCursorName);
if (handle == 0) {
SWT.error(SWT.ERROR_NO_HANDLES);
}
return new CustomCursorHandle(handle);
return lpCursorName;
}
}

Expand All @@ -639,13 +588,24 @@ protected final int getHotpotXInPixels(int zoom) {
protected final int getHotpotYInPixels(int zoom) {
return Win32DPIUtils.pointToPixel(hotspotY, zoom);
}

protected static final void validateHotspotInsideImage(ImageData source, int hotspotX, int hotspotY) {
/* Check the hotspots */
if (hotspotX >= source.width || hotspotX < 0 ||
hotspotY >= source.height || hotspotY < 0) {
SWT.error(SWT.ERROR_INVALID_ARGUMENT);
}
}
}

private static class ImageDataProviderCursorHandleProvider extends HotspotAwareCursorHandleProvider {
private final ImageDataProvider provider;

public ImageDataProviderCursorHandleProvider(ImageDataProvider provider, int hotspotX, int hotspotY) {
super(hotspotX, hotspotY);
ImageData source = provider.getImageData(DEFAULT_ZOOM);
if (source == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
validateHotspotInsideImage(source, hotspotX, hotspotY);
this.provider = provider;
}

Expand All @@ -668,6 +628,8 @@ private static class ImageDataCursorHandleProvider extends HotspotAwareCursorHan

public ImageDataCursorHandleProvider(ImageData source, int hotspotX, int hotspotY) {
super(hotspotX, hotspotY);
if (source == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
validateHotspotInsideImage(source, hotspotX, hotspotY);
this.source = source;
}

Expand All @@ -685,6 +647,21 @@ private static class ImageDataWithMaskCursorHandleProvider extends ImageDataCurs
public ImageDataWithMaskCursorHandleProvider(ImageData source, ImageData mask, int hotspotX, int hotspotY) {
super(source, hotspotX, hotspotY);
this.mask = mask;
validateMask(source, mask);
}

private void validateMask(ImageData source, ImageData mask) {
ImageData testMask = mask == null ? null : (ImageData) mask.clone();
if (testMask == null) {
if (source.getTransparencyType() != SWT.TRANSPARENCY_MASK) {
SWT.error(SWT.ERROR_NULL_ARGUMENT);
}
testMask = source.getTransparencyMask();
}
/* Check the bounds. Mask must be the same size as source */
if (testMask.width != source.width || testMask.height != source.height) {
SWT.error(SWT.ERROR_INVALID_ARGUMENT);
}
}

@Override
Expand Down
62 changes: 62 additions & 0 deletions ...t.tests/JUnit Tests/org/eclipse/swt/tests/junit/Test_org_eclipse_swt_graphics_Cursor.java
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -28,6 +28,8 @@
import org.eclipse.swt.graphics.ImageData;
import org.eclipse.swt.graphics.ImageDataProvider;
import org.eclipse.swt.graphics.ImageLoader;
import org.eclipse.swt.graphics.PaletteData;
import org.eclipse.swt.graphics.RGB;
import org.eclipse.swt.widgets.Display;
import org.junit.Before;
import org.junit.Test;
Expand Down Expand Up @@ -162,6 +164,66 @@ public void test_ConstructorWithImageDataProvider() {
IllegalArgumentException.class, () -> new Cursor(display, (ImageDataProvider) null, 0, 0));
}

@Test
public void test_InvalidArgumentsForAllConstructors() {
ImageData source = new ImageData(16, 16, 1, new PaletteData(new RGB[] { new RGB(0, 0, 0) }));
ImageData mask = new ImageData(16, 16, 1, new PaletteData(new RGB[] { new RGB(0, 0, 0) }));

assertThrows("When wrong style was provided", IllegalArgumentException.class,
() -> {
Cursor cursor = new Cursor(Display.getDefault(), -99);
cursor.dispose();
});

assertThrows("When source is null", IllegalArgumentException.class, () -> {
Cursor cursorFromImageAndMask = new Cursor(Display.getDefault(), null, mask, 0, 0);
cursorFromImageAndMask.dispose();
});

assertThrows("When mask is null and source doesn't heve a mask",
IllegalArgumentException.class, () -> {
Cursor cursorFromImageAndMask = new Cursor(Display.getDefault(), source, null, 0, 0);
cursorFromImageAndMask.dispose();
});

assertThrows("When source and the mask are not the same size",
IllegalArgumentException.class, () -> {
ImageData source32 = new ImageData(32, 32, 1, new PaletteData(new RGB[] { new RGB(0, 0, 0) }));
ImageData mask16 = new ImageData(16, 16, 1, new PaletteData(new RGB[] { new RGB(0, 0, 0) }));

Cursor cursorFromImageAndMask = new Cursor(Display.getDefault(), source32, mask16, 0, 0);
cursorFromImageAndMask.dispose();
});

assertThrows("When hotspot is outside the bounds of the image",
IllegalArgumentException.class, () -> {
Cursor cursorFromImageAndMask = new Cursor(Display.getDefault(), source, mask, 18, 18);
cursorFromImageAndMask.dispose();
});

assertThrows("When source image data is null", IllegalArgumentException.class,
() -> {
ImageData nullImageData = null;
Cursor cursorFromSourceOnly = new Cursor(Display.getDefault(), nullImageData, 0, 0);
cursorFromSourceOnly.dispose();
});

assertThrows("When ImageDataProvider is null", IllegalArgumentException.class,
() -> {
ImageDataProvider provider = null;
Cursor cursorFromProvider = new Cursor(Display.getDefault(), provider, 0, 0);
cursorFromProvider.dispose();
});

assertThrows("When source in ImageDataProvider is null",
IllegalArgumentException.class, () -> {
ImageData nullSource = null;
ImageDataProvider provider = zoom -> nullSource;
Cursor cursorFromProvider = new Cursor(Display.getDefault(), provider, 0, 0);
cursorFromProvider.dispose();
});
}

@Test
public void test_equalsLjava_lang_Object() {
/* Note: Two cursors are only considered equal if their handles are equal.
Expand Down
Loading