+The window server runs continuously and brings the machine down if it
+crashes, so it cannot panic its own thread when it detects an error in one of
+its client’s requests. Instead it panics the client’s thread using
+CSession::Panic(). These panics have a category of WSERV.
+
+These panics are defined in the enumeration TClientPanic in
+w32cmd.h.
+
+Note that some panics are raised in debug builds only. +
+1
++Out of range opcode. +
++The client has sent a request opcode that wasn’t recognised. Each +server-side object can only handle some of the requests defined in the window +server, and if the request isn’t recognised, this panic is raised. +
++Clients would normally only get this is if they bypass the normal +Window Server API. +
+2
++Invalid command buffer. +
++A corrupt buffer of requests was discovered by the server. This is +raised when the buffer itself is noticeably broken, and not when the commands +in it are wrong. +
+3
++Invalid handle. +
++The server couldn’t find the target object for a request in the +handle index. This can be raised when a command is sent to the handle for a +window that has been closed, for example. +
+4
++A handle whose value was NULL was detected. +
+
+For example, when Constructing one of the subclasses of the
+client-side RWindowBase with a client handle argument of
+NULL.
+
+On the server side, a TWsClCmdCreateWindow with a
+client handle field of NULL passed as argument to
+CWsClientWindow::ConstructL() will raise this error.
+
5
++A single drawing command was too big to fit into the +client-side buffer. +
+
+The size of the buffer may be increased. See
+RWsSession::SetBufferSizeL() and
+RWsSession::SetMaxBufferSizeL().
+
6
++Invalid window handle. +
++A handle which should have referred to a window of a particular +type referred to a window of another type, or the object index didn’t recognise +the handle. +
+
+On the server side, this panic is ultimately raised by
+CWsClient::HandleToWindow() and
+CWsClient::HandleToClientWindow() during handle conversions.
+
7
++Invalid bitmap handle. +
++A corrupt bitmap handle was encountered. This is a common panic +uncovered when a bitmap handle refers to nothing, or to a server-side object +that isn’t a bitmap. +
++Also: +
+
+In response to an EWsGcOpUseBrushPattern request
+if the bitmap parameter couldn’t be used. On the client side,
+CWindowGc::UseBrushPattern() sends this request.
+
+In response to an EWsSpriteOpAppendMember request
+when the bitmaps for the sprite member can't be created on the server side. On
+the client side, RWsSpriteBase::AppendMember() sends this
+request.
+
+Any failed attempt to duplicate a supplied bitmap. +
+8
++Event read already outstanding. +
+
+RWsSession::EventReady(),
+RWsSession::RedrawReady(), or
+RWsSession::PriorityKeyReady() was called again when an
+event read was already outstanding, i.e.. when an event was waiting to be
+delivered by the window server.
+
9
++Attempted to use a non-active graphics context. +
++A drawing request was sent to a graphics context when the context +was not active. +
+
+On the server side, this panic is raised by
+CWsGc::CommandL() on all requests received when the context isn’t
+active except EWsGcOpActivate, EWsGcOpDeactivate,
+EWsGcOpFree, and EWsGcOpTestInvariant.
+
10
++Attempted to activate an already active graphics context. +
+
+On the server side, this is raised by
+CWsGc::Activate() as a response to a EWsGcOpActivate
+
+request.
+
+The request is sent by the client-side method
+CWindowGc::Activate().
+
11
++Window already active. +
+
+An attempt was made to reactivate an active window. The request is
+sent by the client-side method RWindowBase::Activate().
+
+On the server side, this panic is raised by
+CWsClientWindow::Activate() in response to an
+EWsWinOpActivate request.
+
12
++Already inside a begin/end redraw pair. +
+
+A begin-redraw window request was made when the window had already
+begun redrawing. Begin-redraw messages are paired with end-redraw messages, and
+ordering is important. Invoking RWindow::BeginRedraw(),
+then RWindow::BeginRedraw() again before the corresponding
+RWindow::EndRedraw() raises this panic.
+
+On the server side, this panic is raised if an
+EWsWinOpBeginRedraw request is sent twice before the closing
+EWsWinOpEndRedraw
+.
+
13
++Invalid font handle. +
+
+On the client-side is raised if
+CWindowGc::UseFont() is called with an invalid font
+handle.
+
+On the server side, CWsGc::SetGcAttribute() raises
+this error in response to an EWsGcOpUseFont request.
+
14
++Printing with no active font. +
+
+A command to draw text to a window was sent to a graphics context
+when no font was set. Any of the overloads of
+CWindowGc::DrawTextVertical() or
+CWindowGc::DrawText() might cause the panic to be raised;
+the font should be set using CWindowGc::UseFont() first.
+
+On the server side, this panic is raised by
+CWsGc::DoDrawCommand() in response to any of the requests to
+display text defined in TWsGcOpcodes.
+
15
+
+Attempted to set an invalid text cursor type, see
+RWindowGroup::SetTextCursor().
+
+Valid types are defined in the TTextCursor
+struct.
+
16
++A drawing command was sent to a graphics context active on a group +window. +
+17
++Not used. +
+18
++Not used. +
+19
+
+Attempted to use a patterned brush when the pattern bitmap has not
+yet been set — UseBrushPattern().
+
20
++Not used. +
+21
++Attempted to do a client destroy function on an illegal handle. +
++A client tried to destroy or cancel a server-side object by its +handle on an unrecognised handle, or on a handle of the wrong type for the +operation. +
+
+This panic may be caused by the
+RWindowGroup::CancelCaptureKeyUpAndDowns() or
+RWindowGroup::CancelCaptureKey() methods. These correspond
+to the EWsWinOpCancelCaptureKeyUpsAndDowns and
+EWsWinOpCancelCaptureKey server requests. In this case, the panic
+means that there is no such capture key object in existence in the target
+window group.
+
22
++Panic from the Anim DLL. +
+
+An animation DLL tried either changing its default or next timing
+interval when its timing mode was set to ESyncNone, or activating
+a graphics context when the context was already activated.
+
+There are a variety of other reasons why this panic might be +raised, all which are Anim DLL related. The Animation writer can also cause +functions raise this panic. +
+23
++Invalid Anim object handle. +
+
+A null animation handle was detected in the server on receipt of an
+animation command, possibly because the relevant animation has been deleted.
+This panic may be raised by a subclass of RAnim calling
+RAnim::Command() or
+RAnim::CommandReply().
+
+On the server side, the EWsAnimDllOpCommandReply and
+EWsAnimDllOpCommand requests can raise this panic in
+CWsAnimDll
+.
+
24
++Leave from a non-leaving animation function. +
+
+Code in an animated DLL called by the server invoked
+Leave(). Animated DLL code is provided by the client and run by
+the server, so unhandled leaves are trapped and the notification is passed on
+as a client panic.
+
25
++Not used. +
+26
++Not used. +
+27
++Not used. +
+28
++Inconsistent polygon or polyline data was supplied. For example +when restarting without finishing an old polygon. +
+29
++A client attempted to set a negative shadow height. +
+
+This panic is caused by a call to
+RWindowBase::SetShadowHeight() with a negative argument.
+
+On the server side, CWsClientWindow::CommandL() raises
+the panic in response to an invalid EWsWinOpSetShadowHeight
+request.
+
30
++Not used. +
+31
+
+The client tried to construct a window with an invalid redraw type.
+The valid redraw types defined in the enumeration TWinTypes of
+w32cmd.h
+.
+
+On the server side, this panic is raised by
+CWsClientWindow::ConstructL() in response to an initialisation
+message containing an invalid redraw type.
+
32
++A server-side redraw region is almost certainly corrupt. +
+
+This panic is raised when an EWsWinOpGetInvalidRegion
+is received by a CWsRedrawMsgWindow with a TInt
+parameter of zero or less.
+
33
++The client failed to provide a reply buffer to a server-side +function when one was needed. +
+
+All server-side functions that need more space for their reply than
+a TInt use the client’s reply buffer. If the client fails to
+provide space for such replies, this panic will be emitted.
+
+This panic is raised by CWsClient::ReplyBuf() when
+CWsClient’s reply buffer is null.
+
34
++Not used. +
+35
++A client passed an invalid or unrecognised corner type or flag. +
+
+This panic is raised in response to a client call to
+RWindowBase::SetCornerType() when specifying inconsistent
+or non-existent flags.
+
+Valid flags are masked by ECornerTypeMask, and
+recognised types are defined in TCornerType. These are all
+defined in w32std.h.
+
+The server raises this panic as a response to
+EWsWinOpSetCornerType request with an undefined corner type or an
+unrecognised flag in its parameters.
+
36
++The server was asked to update a region of a backed-up window which +has not had MaintainBackup called on it. +
+
+A client-side call to either form of
+RBackedUpWindow::UpdateScreen() may raise this panic.
+
+On the server side, the panic is raised in response to an
+EWsWinOpUpdateScreenRegion or EWsWinOpUpdateScreen
+
+request when not maintaining a full backup of a backed-up window.
+
37
++Panic raised when it was not possible to read or write data to the +client thread. The data is usually contained in a descriptor. +
+38
++The client attempted to access a sprite after the sprite's window +was destroyed. Note that pointer cursors are implemented as sprites. +
+39
++A client requested event data without having received an event +telling it that the data was ready. +
+40
++The mask for a sprite is smaller than the sprite’s bitmap. A mask +is permitted to be larger than its bitmap. +
+41
++Bad sprite handle. +
++A null sprite handle was encountered, or a handle which was +supposed to refer to a sprite referred to something else. +
+
+The client-side methods
+RWindowTreeNode::SetCustomPointerCursor() and
+RWsSession::SetSystemPointerCursor(), amongst others, can
+cause this panic to be raised; they correspond to the server requests
+EWsWinOpSetCustomPointerCursor and
+EWsClOpSetSystemPointerCursor.
+
42
++A client attempted to set or clear a system pointer cursor without +first owning the list of system pointer cursors. +
+
+RWsSession::SetSystemPointerCursor() and
+RWsSession::ClearSystemPointerCursor() can raise this
+panic. See also RWsSession::ClaimSystemPointerCursorList()
+and RWsSession::FreeSystemPointerCursorList().
+
+The server requests which can raise this panic are
+EWsClOpSetSystemPointerCursor and
+EWsClOpClearSystemPointerCursor.
+
43
++A client attempted to enable a pointer move buffer when none was +allocated. +
+
+RWindowBase::EnablePointerMoveBuffer() can
+cause this panic to be emitted; the corresponding server request is
+EWsWinOpEnablePointerMoveBuffer.
+
44
++Raised in response to commands that send a string, when the string +has been incorrectly stored in the command buffer. +
+45
++Not used. +
+46
+
+An invalid call or request parameter was detected by
+CWsPassword. This can be caused:
+
+By RWindowBase::PasswordWindow() sending
+an EWsWinOpPasswordWindow server request whose password mode
+parameter is not recognised.
+
+By an attempt to cancel the password window by a client which +doesn’t own the window. +
+
+By RWsSession::PasswordEntered() sending a
+EWsClOpPasswordEntered server request when no password window has
+been set, or when the client does not own the password window.
+
+Valid password modes are defined in
+TPasswordMode of w32std.h.
+
47
+
+An invalid compute mode was sent to the window server. On the
+client side, RWsSession::ComputeMode() can do this, the
+window server request is EWsClOpComputeMode. Valid compute modes
+are defined in the enumeration RWsSession::TComputeMode,
+which is declared in w32std.h.
+
48
+
+A client attempted to set the display mode of a backed-up window.
+This can be done with
+RWindowBase::SetRequiredDisplayMode() or the
+EWsWinOpRequiredDisplayMode server request.
+
49
++A client attempted to get a message when has not been signalled in +the server. +
+
+This panic can be raised on a client thread calling
+RWindowGroup::FetchMessage() or sending the
+EWsWinOpGetMessageSize or EWsWinOpGetMessage
+ messages.
+
50
+
+A client tried to send a second initialisation message, i.e. to
+call RWsSession::Connect() twice.
+
51
++A client attempted to send a message without specifying a target +window. +
+
+This can be raised, for example, in response to
+RWsSession::RequestOffEvents()
+
52
++A client attempted to perform and operation on a window that has +had its parent or ancestor deleted. An operation which might raise this panic +could be setting the window size, position or extent. +
++Introduced in v5.1 +
+53
+
+A client attempted to reset a window group’s default owning window.
+For example, by calling the function
+RWindowGroup::DefaultOwningWindow() twice on the same
+window group.
+
+This is only raised in debug builds. +
+54
++A client attempted to perform an operation on an invalid screen +mode. +
+
+For example, if the client called the functions
+CWsScreenDevice::GetScreenModeSizeAndRotation() or
+CWsScreenDevice::SetScreenMode() with an illegal index.
+
+Introduced in v5.1 +
+55
++A client attempted to set an invalid screen enforcement mode. +
+
+The valid screen mode enforcement modes are defined in
+TScreenModeEnforcement.
+
+Introduced in v5.1 +
+56
+
+A client specified an event type which was not a pointer event,
+when this is what was required by the operation. e.g.
+RWindowGroup::SimulatePointerEvent().
+
+Introduced in v5.1 +
+57
++A client attempted to specify a screen rotation or orientation that +is not allowed. Each screen size mode has a list of allowed rotations. +
++Introduced in v5.1 +
+58
+
+A client attempted to call a function that can only be called on a
+top level client window on a lower level window. A top level client window is a
+window with a window group as a parent, e.g.
+RWindowBase::MoveToGroup().
+
+Introduced in v6.0 +
+59
+
+A client attempted to use a
+RDirectScreenAccess object's member functions in the wrong
+order.
+
+Introduced in v7.0 +
+60
++The handle to a window server resource is already in use (debug +builds only). +
++Introduced in v7.0 +
+61
+
+An attempt was made to set a custom text cursor (using
+RWindowGroup::SetTextCursor()) but the cursor's type was
+not recognised.
+
+Introduced in v7.0s. +
+62
+
+An attempt was made to set a custom text cursor (using
+RWindowGroup::SetTextCursor()) whose alignment value is
+invalid. For valid alignment values see the
+TCustomTextCursorAlignment enumeration in class
+RWsSession.
+
+Introduced in v7.0s. +
+63
+
+An attempt was made to set a custom text cursor (using
+RWindowGroup::SetTextCursor()) that does not have any
+sprite members set.
+
+Introduced in v7.0s.
\ No newline at end of file