tdf#149952 gtk3 a11y: Return pos relative to window when requested

ATK (and AT-SPI) allows to specify 3 different coordinate
types [1]:

1) `ATK_XY_SCREEN`: coordinates relative to the screen.
2) `ATK_XY_WINDOW`: coordinates relative to the widget's
top-level window.
3) `ATK_XY_PARENT` coordinates relative to the widget's
immediate parent.

The `XAccessibleComponent` interface provides equivalents
for 1) and 3), but not 2), and the gtk3 VCL plugin wasn't
really handling 2) so far either.

This adds handling for `ATK_XY_WINDOW`. The position
in the window is calculated by recursively walking up the a11y
hierarchy and summing up the positions relative to the
parent, until a window is reached (or there's no parent,
or none implementing `AtkComponent`).

Also add an explicit check for `ATK_XY_PARENT` if
none of the other two constants is used and warn
and return if that isn't used either, to cover the case
that new constants will be introduced in newer ATK versions.
(That check needs to be conditional, because `ATK_XY_PARENT`
is only defined from ATK 2.30 on, while our minimum
required version is currently 2.28.1.)

The coordinates received when testing this with a
selected Writer paragraph in Accerciser's IPython console
look generally plausible now with this change in place:

In [108]: acc.queryComponent().getPosition(pyatspi.component.XY_SCREEN)
Out[109]: (1939, 417)
In [109]: acc.queryComponent().getPosition(pyatspi.component.XY_WINDOW)
Out[110]: (19, 245)
In [110]: acc.queryComponent().getPosition(pyatspi.component.XY_PARENT)
Out[111]: (19, 113)
In [111]: acc.queryText().getCharacterExtents(0, pyatspi.component.XY_SCREEN)
Out[112]: (2015, 417, 5, 19)
In [112]: acc.queryText().getCharacterExtents(0, pyatspi.component.XY_WINDOW)
Out[113]: (95, 245, 5, 19)
In [113]: acc.queryText().getCharacterExtents(0, pyatspi.component.XY_PARENT)
Out[114]: (76, 0, 5, 19)

(Previously, requesting window-relative coordinates gave the
same result as coordinates relative to direct parent.)

[1] https://docs.gtk.org/atk/enum.CoordType.html

Change-Id: Idf8f7d08f9054a8df28d1ee8fccc791a803de045
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/137027
Tested-by: Jenkins
Reviewed-by: Michael Weghorn <m.weghorn@posteo.de>
(cherry picked from commit 7b312771d7eb33f7410167e36efdaeca6f540b1c)
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/137061
Reviewed-by: Caolán McNamara <caolanm@redhat.com>

2 files changed, 49 insertions, 5 deletions

diff --git a/vcl/unx/gtk3/a11y/atkcomponent.cxx b/vcl/unx/gtk3/a11y/atkcomponent.cxx
index 21301d4da6bb..154f0117f1bc 100644
--- a/vcl/unx/gtk3/a11y/atkcomponent.cxx
+++ b/vcl/unx/gtk3/a11y/atkcomponent.cxx
@@ -19,6 +19,7 @@
 
 #include "atkwrapper.hxx"
 #include <com/sun/star/accessibility/XAccessibleComponent.hpp>
+#include <sal/log.hxx>
 #include <gtk/gtk.h>
 
 using namespace ::com::sun::star;
@@ -51,15 +52,41 @@ static css::uno::Reference<css::accessibility::XAccessibleComponent>
     return css::uno::Reference<css::accessibility::XAccessibleComponent>();
 }
 
+static awt::Point
+lcl_getLocationInWindow(AtkComponent* pAtkComponent,
+                        css::uno::Reference<accessibility::XAccessibleComponent> const& xComponent)
+{
+    // calculate position in window by adding the component's position in the parent
+    // to the parent's position in the window (unless parent is a window itself)
+    awt::Point aPos = xComponent->getLocation();
+    AtkObject* pParent = atk_object_get_parent(ATK_OBJECT(pAtkComponent));
+    if (ATK_IS_COMPONENT(pParent) && pParent->role != AtkRole::ATK_ROLE_DIALOG
+            && pParent->role != AtkRole::ATK_ROLE_FILE_CHOOSER
+            && pParent->role != AtkRole::ATK_ROLE_FRAME
+            && pParent->role != AtkRole::ATK_ROLE_WINDOW)
+    {
+        int nX;
+        int nY;
+        atk_component_get_extents(ATK_COMPONENT(pParent), &nX, &nY, nullptr, nullptr, ATK_XY_WINDOW);
+        aPos.X += nX;
+        aPos.Y += nY;
+    }
+
+    return aPos;
+}
+
 /*****************************************************************************/
 
 static awt::Point
-translatePoint( css::uno::Reference<accessibility::XAccessibleComponent> const & pComponent,
+translatePoint( AtkComponent* pAtkComponent,
+                css::uno::Reference<accessibility::XAccessibleComponent> const & pComponent,
                 gint x, gint y, AtkCoordType t)
 {
     awt::Point aOrigin( 0, 0 );
     if( t == ATK_XY_SCREEN )
         aOrigin = pComponent->getLocationOnScreen();
+    else if (t == ATK_XY_WINDOW)
+        aOrigin = lcl_getLocationInWindow(pAtkComponent, pComponent);
     return awt::Point( x - aOrigin.X, y - aOrigin.Y );
 }
 
@@ -111,7 +138,8 @@ component_wrapper_contains (AtkComponent *component,
         css::uno::Reference<css::accessibility::XAccessibleComponent> pComponent
             = getComponent(obj);
         if( pComponent.is() )
-            return pComponent->containsPoint( translatePoint( pComponent, x, y, coord_type ) );
+            return pComponent->containsPoint(
+                translatePoint(component, pComponent, x, y, coord_type));
     }
     catch( const uno::Exception & )
     {
@@ -142,7 +170,7 @@ component_wrapper_ref_accessible_at_point (AtkComponent *component,
         if( pComponent.is() )
         {
             uno::Reference< accessibility::XAccessible > xAccessible = pComponent->getAccessibleAtPoint(
-                translatePoint( pComponent, x, y, coord_type ) );
+                translatePoint(component, pComponent, x, y, coord_type));
             return atk_object_wrapper_ref( xAccessible );
         }
     }
@@ -182,8 +210,24 @@ component_wrapper_get_position (AtkComponent   *component,
 
             if( coord_type == ATK_XY_SCREEN )
                 aPos = pComponent->getLocationOnScreen();
+            else if (coord_type == ATK_XY_WINDOW)
+                aPos = lcl_getLocationInWindow(component, pComponent);
+#if ATK_CHECK_VERSION(2, 30, 0)
+            else if (coord_type == ATK_XY_PARENT)
+#else
+            // ATK_XY_PARENT added in ATK 2.30, so can't use the constant here
             else
+#endif
                 aPos = pComponent->getLocation();
+#if ATK_CHECK_VERSION(2, 30, 0)
+            else
+            {
+                SAL_WARN("vcl.gtk",
+                         "component_wrapper_get_position called with unknown AtkCoordType "
+                             << coord_type);
+                return;
+            }
+#endif
 
             *x = aPos.X;
             *y = aPos.Y;
diff --git a/vcl/unx/gtk3/a11y/atktext.cxx b/vcl/unx/gtk3/a11y/atktext.cxx
index 713b03325518..ecbb6cd6ed60 100644
--- a/vcl/unx/gtk3/a11y/atktext.cxx
+++ b/vcl/unx/gtk3/a11y/atktext.cxx
@@ -666,7 +666,7 @@ text_wrapper_get_character_extents( AtkText          *text,
             gint origin_x = 0;
             gint origin_y = 0;
 
-            if( coords == ATK_XY_SCREEN )
+            if (coords == ATK_XY_SCREEN || coords == ATK_XY_WINDOW)
             {
                 g_return_if_fail( ATK_IS_COMPONENT( text ) );
                 SAL_WNODEPRECATED_DECLARATIONS_PUSH
@@ -717,7 +717,7 @@ text_wrapper_get_offset_at_point (AtkText     *text,
             gint origin_x = 0;
             gint origin_y = 0;
 
-            if( coords == ATK_XY_SCREEN )
+            if (coords == ATK_XY_SCREEN || coords == ATK_XY_WINDOW)
             {
                 g_return_val_if_fail( ATK_IS_COMPONENT( text ), -1 );
                 SAL_WNODEPRECATED_DECLARATIONS_PUSH