office-gobmx/vcl/inc/salframe.hxx
Michael Weghorn bfbaeb8192 tdf#160982 wina11y: Drop extra screen reader check to enable a11y bridge
When initializing the a11y bridge on Windows, no longer
check whether the screen reader parameter
`SPI_GETSCREENREADER` [1] is explicitly set or require
to explicitly enable by setting an
`SAL_FORCE_IACCESSIBLE2` environment variable.

For performance reasons, it of course makes sense to only
enable the a11y bridge when there is actually assistive
technology that makes use of it.

However, `ImplInitAccessBridge` already only gets called
when either support for assistive technology has explicitly
been enabled in the settings (i.e. in "Tools" -> "Options" -> "LibreOfficeDev"
-> "Accessibility", the "Support assistive technology tools (restart
required" checkbox was checked) or when a `WM_GETOBJECT` message
is received, whose documentation says [2]:

> Sent by both Microsoft Active Accessibility and Microsoft UI Automation
> to obtain information about an accessible object contained in a server
> application.
>
> Applications never send this message directly. Microsoft Active
> Accessibility sends this message in response to calls to
> AccessibleObjectFromPoint, AccessibleObjectFromEvent, or
> AccessibleObjectFromWindow. However, server applications handle this
> message. UI Automation sends this message in response to calls to
> IUIAutomation::ElementFromHandle, ElementFromPoint, and
> GetFocusedElement, and when handling events for which a client has
> registered.

Both of these cases (explicitly enabled, AT requests information) justify
enabling the a11y bridge by themselves, so drop the extra check.

Qt's UIA bridge for example also gets activated when a WM_GETOBJECT
message is received [3].

This makes both, Microsoft Narrator (screen reader shipped with
Windows, but which doesn't set the `SPI_GETSCREENREADER` parameter)
and Microsoft Accessibility Insights for Windows (a tool for a11y
analysis/debugging) work - at least to a certain degree - without
having to explicitly set the environment variable
`SAL_FORCE_IACCESSIBLE2`.

While LibreOffice doesn't have a UIA bridge at this point in time,
Windows provides an MSAA (IAccessible) to UIA proxy that provides
some basic information via UIA at least, see [4]:

> The LegacyIAccessible control pattern is supported by the Microsoft
> Active Accessibility to Microsoft UI Automation Proxy.

As expected, a breakpoint or assert in `ImplInitAccessBridge`
only got hit in my testing when either an AT was active or the
above-mentioned option was explicitly enabled, not otherwise when
starting or using LO.

[1] https://learn.microsoft.com/en-us/windows/win32/winauto/screen-reader-parameter
[2] https://learn.microsoft.com/en-us/windows/win32/winauto/wm-getobject
[3] https://code.qt.io/cgit/qt/qtbase.git/tree/src/plugins/platforms/windows/uiautomation/qwindowsuiaaccessibility.cpp?id=e9662a4b665144a5eca418925d331024ec71fa2c#n40
[4] https://learn.microsoft.com/en-us/windows/win32/winauto/uiauto-implementinglegacyiaccessible

Change-Id: Iddafb149b50771412ba59972d0401bada6a9f680
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/175172
Tested-by: Jenkins
Reviewed-by: Michael Weghorn <m.weghorn@posteo.de>
2024-10-19 08:48:46 +02:00

331 lines
13 KiB
C++

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
* This file is part of the LibreOffice project.
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*
* This file incorporates work covered by the following license notice:
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed
* with this work for additional information regarding copyright
* ownership. The ASF licenses this file to you under the Apache
* License, Version 2.0 (the "License"); you may not use this file
* except in compliance with the License. You may obtain a copy of
* the License at http://www.apache.org/licenses/LICENSE-2.0 .
*/
#ifndef INCLUDED_VCL_INC_SALFRAME_HXX
#define INCLUDED_VCL_INC_SALFRAME_HXX
#include "impdel.hxx"
#include "salwtype.hxx"
#include "salgeom.hxx"
#include <vcl/help.hxx>
#include <o3tl/typed_flags_set.hxx>
#include <vcl/window.hxx>
// complete vcl::Window for SalFrame::CallCallback under -fsanitize=function
class AllSettings;
class SalGraphics;
class SalBitmap;
class SalMenu;
namespace vcl { class WindowData; }
struct SalInputContext;
struct SystemEnvData;
// SalFrame types
enum class SalFrameToTop {
NONE = 0x00,
RestoreWhenMin = 0x01,
ForegroundTask = 0x02,
GrabFocus = 0x04,
GrabFocusOnly = 0x08
};
namespace o3tl {
template<> struct typed_flags<SalFrameToTop> : is_typed_flags<SalFrameToTop, 0x0f> {};
};
namespace vcl { class KeyCode; }
namespace weld
{
class Window;
}
enum class FloatWinPopupFlags;
// SalFrame styles
enum class SalFrameStyleFlags
{
NONE = 0x00000000,
DEFAULT = 0x00000001,
MOVEABLE = 0x00000002,
SIZEABLE = 0x00000004,
CLOSEABLE = 0x00000008,
// no shadow effect on Windows XP
NOSHADOW = 0x00000010,
// indicate tooltip windows, so they can always be topmost
TOOLTIP = 0x00000020,
// windows without windowmanager decoration, this typically only applies to floating windows
OWNERDRAWDECORATION = 0x00000040,
// dialogs
DIALOG = 0x00000080,
// the window containing the intro bitmap, aka splashscreen
INTRO = 0x00000100,
// tdf#144624: don't set icon
NOICON = 0x01000000,
// system child window inside another SalFrame
SYSTEMCHILD = 0x08000000,
// plugged system child window
PLUG = 0x10000000,
// floating window
FLOAT = 0x20000000,
// toolwindows should be painted with a smaller decoration
TOOLWINDOW = 0x40000000,
};
namespace o3tl {
template<> struct typed_flags<SalFrameStyleFlags> : is_typed_flags<SalFrameStyleFlags, 0x798001ff> {};
};
// Extended frame style (sal equivalent to extended WinBits)
typedef sal_uInt64 SalExtStyle;
#define SAL_FRAME_EXT_STYLE_DOCUMENT SalExtStyle(0x00000001)
#define SAL_FRAME_EXT_STYLE_DOCMODIFIED SalExtStyle(0x00000002)
// Flags for SetPosSize
#define SAL_FRAME_POSSIZE_X (sal_uInt16(0x0001))
#define SAL_FRAME_POSSIZE_Y (sal_uInt16(0x0002))
#define SAL_FRAME_POSSIZE_WIDTH (sal_uInt16(0x0004))
#define SAL_FRAME_POSSIZE_HEIGHT (sal_uInt16(0x0008))
struct SystemParentData;
struct ImplSVEvent;
/// A SalFrame is a system window (e.g. an X11 window).
class VCL_PLUGIN_PUBLIC SalFrame
: public vcl::DeletionNotifier
, public SalGeometryProvider
{
private:
// the VCL window corresponding to this frame
VclPtr<vcl::Window> m_pWindow;
SALFRAMEPROC m_pProc;
Link<bool, void> m_aModalHierarchyHdl;
protected:
// subclasses need to either keep this up to date
// or override GetUnmirroredGeometry()
SalFrameGeometry maGeometry; ///< absolute, unmirrored values
mutable std::unique_ptr<weld::Window> m_xFrameWeld;
public:
SalFrame();
virtual ~SalFrame() override;
// SalGeometryProvider
virtual tools::Long GetWidth() const override { return GetUnmirroredGeometry().width(); }
virtual tools::Long GetHeight() const override { return GetUnmirroredGeometry().height(); }
virtual bool IsOffScreen() const override { return false; }
// SalGraphics or NULL, but two Graphics for all SalFrames
// must be returned
virtual SalGraphics* AcquireGraphics() = 0;
virtual void ReleaseGraphics( SalGraphics* pGraphics ) = 0;
// Event must be destroyed, when Frame is destroyed
// When Event is called, SalInstance::Yield() must be returned
virtual bool PostEvent(std::unique_ptr<ImplSVEvent> pData) = 0;
virtual void SetTitle( const OUString& rTitle ) = 0;
virtual void SetIcon( sal_uInt16 nIcon ) = 0;
virtual void SetRepresentedURL( const OUString& );
virtual void SetMenu( SalMenu *pSalMenu ) = 0;
virtual void SetExtendedFrameStyle( SalExtStyle nExtStyle ) = 0;
// Before the window is visible, a resize event
// must be sent with the correct size
virtual void Show( bool bVisible, bool bNoActivate = false ) = 0;
// Set ClientSize and Center the Window to the desktop
// and send/post a resize message
virtual void SetMinClientSize( tools::Long nWidth, tools::Long nHeight ) = 0;
virtual void SetMaxClientSize( tools::Long nWidth, tools::Long nHeight ) = 0;
virtual void SetPosSize( tools::Long nX, tools::Long nY, tools::Long nWidth, tools::Long nHeight, sal_uInt16 nFlags ) = 0;
static OUString DumpSetPosSize(tools::Long nX, tools::Long nY, tools::Long nWidth, tools::Long nHeight, sal_uInt16 nFlags);
virtual void GetClientSize( tools::Long& rWidth, tools::Long& rHeight ) = 0;
virtual void GetWorkArea( AbsoluteScreenPixelRectangle& rRect ) = 0;
virtual SalFrame* GetParent() const = 0;
// Note: x will be mirrored at parent if UI mirroring is active
SalFrameGeometry GetGeometry() const;
// subclasses either have to keep maGeometry up to date or override this
// method to return an up-to-date SalFrameGeometry
virtual SalFrameGeometry GetUnmirroredGeometry() const { return maGeometry; }
virtual void SetWindowState(const vcl::WindowData*) = 0;
// return the absolute, unmirrored system frame state
// if this returns false the structure is uninitialised
[[nodiscard]]
virtual bool GetWindowState(vcl::WindowData*) = 0;
virtual void ShowFullScreen( bool bFullScreen, sal_Int32 nDisplay ) = 0;
virtual void PositionByToolkit( const tools::Rectangle&, FloatWinPopupFlags ) {};
// Enable/Disable ScreenSaver, SystemAgents, ...
virtual void StartPresentation( bool bStart ) = 0;
// Show Window over all other Windows
virtual void SetAlwaysOnTop( bool bOnTop ) = 0;
// Window to top and grab focus
virtual void ToTop( SalFrameToTop nFlags ) = 0;
// grab focus to the main widget, can be no-op if the vclplug only uses one widget
virtual void GrabFocus() {}
// this function can call with the same
// pointer style
virtual void SetPointer( PointerStyle ePointerStyle ) = 0;
virtual void CaptureMouse( bool bMouse ) = 0;
virtual void SetPointerPos( tools::Long nX, tools::Long nY ) = 0;
// flush output buffer
virtual void Flush() = 0;
virtual void Flush( const tools::Rectangle& );
virtual void SetInputContext( SalInputContext* pContext ) = 0;
virtual void EndExtTextInput( EndExtTextInputFlags nFlags ) = 0;
virtual OUString GetKeyName( sal_uInt16 nKeyCode ) = 0;
// returns in 'rKeyCode' the single keycode that translates to the given unicode when using a keyboard layout of language 'aLangType'
// returns false if no mapping exists or function not supported
// this is required for advanced menu support
virtual bool MapUnicodeToKeyCode( sal_Unicode aUnicode, LanguageType aLangType, vcl::KeyCode& rKeyCode ) = 0;
// returns the input language used for the last key stroke
// may be LANGUAGE_DONTKNOW if not supported by the OS
virtual LanguageType GetInputLanguage() = 0;
virtual void UpdateSettings( AllSettings& rSettings ) = 0;
virtual void Beep() = 0;
virtual void FlashWindow() const {};
// returns system data (most prominent: window handle)
virtual const SystemEnvData*
GetSystemData() const = 0;
// tdf#139609 SystemEnvData::GetWindowHandle() calls this to on-demand fill the aWindow
// member of SystemEnvData for backends that want to defer doing that
virtual void ResolveWindowHandle(SystemEnvData& /*rData*/) const {};
// get current modifier, button mask and mouse position
struct SalPointerState
{
sal_Int32 mnState;
Point maPos; // in frame coordinates
};
virtual SalPointerState GetPointerState() = 0;
virtual KeyIndicatorState GetIndicatorState() = 0;
virtual void SimulateKeyPress( sal_uInt16 nKeyCode ) = 0;
// set new parent window
virtual void SetParent( SalFrame* pNewParent ) = 0;
// reparent window to act as a plugin; implementation
// may choose to use a new system window internally
// return false to indicate failure
virtual void SetPluginParent( SystemParentData* pNewParent ) = 0;
// move the frame to a new screen
virtual void SetScreenNumber( unsigned int nScreen ) = 0;
virtual void SetApplicationID( const OUString &rApplicationID) = 0;
// shaped system windows
// set clip region to none (-> rectangular windows, normal state)
virtual void ResetClipRegion() = 0;
// start setting the clipregion consisting of nRects rectangles
virtual void BeginSetClipRegion( sal_uInt32 nRects ) = 0;
// add a rectangle to the clip region
virtual void UnionClipRegion( tools::Long nX, tools::Long nY, tools::Long nWidth, tools::Long nHeight ) = 0;
// done setting up the clipregion
virtual void EndSetClipRegion() = 0;
virtual void SetModal(bool /*bModal*/)
{
}
virtual bool GetModal() const
{
return false;
}
// return true to indicate tooltips are shown natively, false otherwise
virtual bool ShowTooltip(const OUString& /*rHelpText*/, const tools::Rectangle& /*rHelpArea*/)
{
return false;
}
// return !0 to indicate popovers are shown natively, 0 otherwise
virtual void* ShowPopover(const OUString& /*rHelpText*/, vcl::Window* /*pParent*/, const tools::Rectangle& /*rHelpArea*/, QuickHelpFlags /*nFlags*/)
{
return nullptr;
}
// return true to indicate popovers are shown natively, false otherwise
virtual bool UpdatePopover(void* /*nId*/, const OUString& /*rHelpText*/, vcl::Window* /*pParent*/, const tools::Rectangle& /*rHelpArea*/)
{
return false;
}
// return true to indicate popovers are shown natively, false otherwise
virtual bool HidePopover(void* /*nId*/)
{
return false;
}
virtual weld::Window* GetFrameWeld() const;
// Callbacks (independent part in vcl/source/window/winproc.cxx)
// for default message handling return 0
void SetCallback( vcl::Window* pWindow, SALFRAMEPROC pProc );
// returns the instance set
vcl::Window* GetWindow() const { return m_pWindow; }
void SetModalHierarchyHdl(const Link<bool, void>& rLink) { m_aModalHierarchyHdl = rLink; }
void NotifyModalHierarchy(bool bModal) { m_aModalHierarchyHdl.Call(bModal); }
virtual void UpdateDarkMode() {}
virtual bool GetUseDarkMode() const { return false; }
virtual bool GetUseReducedAnimation() const { return false; };
// Call the callback set; this sometimes necessary for implementation classes
// that should not know more than necessary about the SalFrame implementation
// (e.g. input methods, printer update handlers).
bool CallCallback( SalEvent nEvent, const void* pEvent ) const
{ return m_pProc && m_pProc( m_pWindow, nEvent, pEvent ); }
// Helper method for input method handling: Calculate cursor index in (UTF-16) OUString,
// starting at nCursorIndex, moving number of characters (not UTF-16 codepoints) specified
// in nOffset, nChars.
static Selection CalcDeleteSurroundingSelection(std::u16string_view rSurroundingText,
sal_Int32 nCursorIndex, int nOffset, int nChars);
virtual void SetTaskBarProgress(int /*nCurrentProgress*/) {}
virtual void SetTaskBarState(VclTaskBarStates /*eTaskBarState*/) {}
};
#endif // INCLUDED_VCL_INC_SALFRAME_HXX
/* vim:set shiftwidth=4 softtabstop=4 expandtab: */