Bug 547557: [GTK] Shell.print(GC) not implemented

Implement Shell.print(GC) using a GdkPixbuf obtained from the root
GdkWindow. This only works on GTK3 + X11, Wayland and GTK4 will likely
need a different approach which will take more time to investigate.

Tested on GTK3.24 on X11, both inside a flatpak and not. Output behaves
as expected, no AllNonBrowser JUnit tests fail.

Change-Id: Ibf39d60f2e97c1ecf8e45c9cdda6da3e9d7e160e
Signed-off-by: Eric Williams <ericwill@redhat.com>

6 files changed, 49 insertions, 0 deletions

diff --git a/bundles/org.eclipse.swt/Eclipse SWT PI/gtk/library/os.c b/bundles/org.eclipse.swt/Eclipse SWT PI/gtk/library/os.c
index f88e3fd40d..9783370d4a 100644
--- a/bundles/org.eclipse.swt/Eclipse SWT PI/gtk/library/os.c
+++ b/bundles/org.eclipse.swt/Eclipse SWT PI/gtk/library/os.c
@@ -1657,6 +1657,18 @@ JNIEXPORT jlong JNICALL GDK_NATIVE(_1gdk_1pixbuf_1get_1byte_1length)
 }
 #endif
 
+#ifndef NO__1gdk_1pixbuf_1get_1from_1window
+JNIEXPORT jlong JNICALL GDK_NATIVE(_1gdk_1pixbuf_1get_1from_1window)
+	(JNIEnv *env, jclass that, jlong arg0, jint arg1, jint arg2, jint arg3, jint arg4)
+{
+	jlong rc = 0;
+	GDK_NATIVE_ENTER(env, that, _1gdk_1pixbuf_1get_1from_1window_FUNC);
+	rc = (jlong)gdk_pixbuf_get_from_window((GdkWindow *)arg0, arg1, arg2, arg3, arg4);
+	GDK_NATIVE_EXIT(env, that, _1gdk_1pixbuf_1get_1from_1window_FUNC);
+	return rc;
+}
+#endif
+
 #ifndef NO__1gdk_1pixbuf_1get_1has_1alpha
 JNIEXPORT jboolean JNICALL GDK_NATIVE(_1gdk_1pixbuf_1get_1has_1alpha)
 	(JNIEnv *env, jclass that, jlong arg0)
diff --git a/bundles/org.eclipse.swt/Eclipse SWT PI/gtk/library/os.h b/bundles/org.eclipse.swt/Eclipse SWT PI/gtk/library/os.h
index 98f86dd750..11abf15d99 100644
--- a/bundles/org.eclipse.swt/Eclipse SWT PI/gtk/library/os.h
+++ b/bundles/org.eclipse.swt/Eclipse SWT PI/gtk/library/os.h
@@ -274,6 +274,7 @@
 #define NO__1gtk_1widget_1style_1get__J_3B_3JJ
 #define NO__1gtk_1css_1provider_1load_1from_1data__I_3BI_3I
 #define NO__1gtk_1css_1provider_1load_1from_1data__J_3BJ_3J
+#define NO__1gdk_1pixbuf_1get_1from_1window
 
 // Some GtkContainer functions don't exist on GTK4
 #define NO__1gtk_1container_1propagate_1draw
diff --git a/bundles/org.eclipse.swt/Eclipse SWT PI/gtk/library/os_stats.c b/bundles/org.eclipse.swt/Eclipse SWT PI/gtk/library/os_stats.c
index 3d9d40141a..9218cda91e 100644
--- a/bundles/org.eclipse.swt/Eclipse SWT PI/gtk/library/os_stats.c
+++ b/bundles/org.eclipse.swt/Eclipse SWT PI/gtk/library/os_stats.c
@@ -136,6 +136,7 @@ char * GDK_nativeFunctionNames[] = {
 	"_1gdk_1pixbuf_1format_1get_1name",
 	"_1gdk_1pixbuf_1get_1bits_1per_1sample",
 	"_1gdk_1pixbuf_1get_1byte_1length",
+	"_1gdk_1pixbuf_1get_1from_1window",
 	"_1gdk_1pixbuf_1get_1has_1alpha",
 	"_1gdk_1pixbuf_1get_1height",
 	"_1gdk_1pixbuf_1get_1n_1channels",
diff --git a/bundles/org.eclipse.swt/Eclipse SWT PI/gtk/library/os_stats.h b/bundles/org.eclipse.swt/Eclipse SWT PI/gtk/library/os_stats.h
index acb253ec53..8fa62cb8c8 100644
--- a/bundles/org.eclipse.swt/Eclipse SWT PI/gtk/library/os_stats.h
+++ b/bundles/org.eclipse.swt/Eclipse SWT PI/gtk/library/os_stats.h
@@ -146,6 +146,7 @@ typedef enum {
 	_1gdk_1pixbuf_1format_1get_1name_FUNC,
 	_1gdk_1pixbuf_1get_1bits_1per_1sample_FUNC,
 	_1gdk_1pixbuf_1get_1byte_1length_FUNC,
+	_1gdk_1pixbuf_1get_1from_1window_FUNC,
 	_1gdk_1pixbuf_1get_1has_1alpha_FUNC,
 	_1gdk_1pixbuf_1get_1height_FUNC,
 	_1gdk_1pixbuf_1get_1n_1channels_FUNC,
diff --git a/bundles/org.eclipse.swt/Eclipse SWT PI/gtk/org/eclipse/swt/internal/gtk/GDK.java b/bundles/org.eclipse.swt/Eclipse SWT PI/gtk/org/eclipse/swt/internal/gtk/GDK.java
index 6132c5c132..e8072b71f8 100644
--- a/bundles/org.eclipse.swt/Eclipse SWT PI/gtk/org/eclipse/swt/internal/gtk/GDK.java
+++ b/bundles/org.eclipse.swt/Eclipse SWT PI/gtk/org/eclipse/swt/internal/gtk/GDK.java
@@ -1548,6 +1548,19 @@ public class GDK extends OS {
 			lock.unlock();
 		}
 	}
+	/**
+	 * @param window cast=(GdkWindow *)
+	 */
+	public static final native long _gdk_pixbuf_get_from_window(long window, int x, int y, int width, int height);
+	/** [GTK3 only, if-def'd in os.h] */
+	public static final long gdk_pixbuf_get_from_window(long window, int x, int y, int width, int height) {
+		lock.lock();
+		try {
+			return _gdk_pixbuf_get_from_window(window, x, y, width, height);
+		} finally {
+			lock.unlock();
+		}
+	}
 	/** @param pixbuf cast=(const GdkPixbuf *) */
 	public static final native int _gdk_pixbuf_get_height(long pixbuf);
 	public static final int gdk_pixbuf_get_height(long pixbuf) {
diff --git a/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/Shell.java b/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/Shell.java
index caa4466520..99f514f3f6 100644
--- a/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/Shell.java
+++ b/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/Shell.java
@@ -1978,6 +1978,27 @@ public boolean print (GC gc) {
 	checkWidget ();
 	if (gc == null) error (SWT.ERROR_NULL_ARGUMENT);
 	if (gc.isDisposed ()) error (SWT.ERROR_INVALID_ARGUMENT);
+	// Needs to be implemented on GTK4/Wayland
+	if (!GTK.GTK4 && OS.isX11()) {
+		Rectangle clipping = gc.getClipping();
+		long shellWindow = gtk_widget_get_window(shellHandle);
+		GdkRectangle rect = new GdkRectangle ();
+		GDK.gdk_window_get_frame_extents (shellWindow, rect);
+		if (clipping.height < rect.height || clipping.width < rect.width) {
+			System.err.println("Warning: the GC provided to Shell.print() has a smaller"
+					+ " clipping than what is needed to print the Shell trimmings"
+					+ " and content. Only the client area will be printed.");
+			return super.print(gc);
+		}
+		long rootWindow = GDK.gdk_get_default_root_window();
+		long pixbuf = GDK.gdk_pixbuf_get_from_window(rootWindow, rect.x, rect.y, rect.width, rect.height);
+		if (pixbuf != 0) {
+			GDK.gdk_cairo_set_source_pixbuf(gc.handle, pixbuf, 0, 0);
+			Cairo.cairo_paint(gc.handle);
+			OS.g_object_unref(pixbuf);
+			return true;
+		}
+	}
 	return false;
 }