深入VCL理解BCB的消息机制2
2013-04-09 15:38
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深入VCL理解BCB的消息机制2
2012-12-25 19:54未知admin
.
关键字：
重载TControl的WndProc方法
还是先谈谈VCL的继承策略。VCL中的继承链的顶部是TObject基类。一切的VCL组件和对象都继承自TObject。
打开BCB帮助查看TControl的继承关系：
TObject->TPersistent->TComponent->TControl
呵呵，原来TControl是从TPersistent类的子类TComponent类继承而来的。TPersistent抽象基类具有使用流stream来存取类的属性的能力。
TComponent类则是所有VCL组件的父类。
这就是所有的VCL组件包括您的自定义组件可以使用dfm文件存取属性的原因『当然要是TPersistent的子类，我想您很少需要直接从TObject类来派生您的自定义组件吧』。
TControl类的重要性并不亚于它的父类们。在BCB的继承关系中，TControl类的是所有VCL可视化组件的父类。实际上就是控件的意思吧。所谓可视化是指您可以在运行期间看到和操纵的控件。这类控件所具有的一些基本属性和方法都在TControl类中进行定义。
TControl的实现在BorlandCBuilder5SourceVclcontrol.pas中可以找到。『可能会有朋友问你怎么知道在那里？使用BCB提供的Search -> Find in files很容易找到。或者使用第三方插件的grep功能。』
好了，进入VCL的源码吧。说到这里免不了要抱怨一下Borland。哎，为什么要用pascal实现这一切.....:-(
TControl继承但并没有重写TObject的Dispatch()方法。反而提供了一个新的方法就是xycleo提到的WndProc()。一起来看看Borland的工程师们是怎么写的吧。
procedure TControl.WndProc(var Message: TMessage);var
Form: TCustomForm;begin//由拥有control的窗体来处理设计期间的消息
if (csDesigning in ComponentState) then
begin
Form := GetParentForm(Self);
if (Form <> nil) and (Form.Designer <> nil) and
Form.Designer.IsDesignMsg(Self, Message) then Exit;
end//如果需要，键盘消息交由拥有control的窗体来处理
else if (Message.Msg >= WM_KEYFIRST) and (Message.Msg <= WM_KEYLAST) then
begin
Form := GetParentForm(Self);
if (Form <> nil) and Form.WantChildKey(Self, Message) then Exit;
end//处理鼠标消息
else if (Message.Msg >= WM_MOUSEFIRST) and (Message.Msg <= WM_MOUSELAST) then
begin
if not (csDoubleClicks in ControlStyle) then
case Message.Msg of
WM_LBUTTONDBLCLK, WM_RBUTTONDBLCLK, WM_MBUTTONDBLCLK:
Dec(Message.Msg, WM_LBUTTONDBLCLK - WM_LBUTTONDOWN);
end;
case Message.Msg of
WM_MOUSEMOVE: Application.HintMouseMessage(Self, Message);
WM_LBUTTONDOWN, WM_LBUTTONDBLCLK:
begin
if FDragMode = dmAutomatic then
begin
BeginAutoDrag;
Exit;
end;
Include(FControlState, csLButtonDown);
end;
WM_LBUTTONUP:
Exclude(FControlState, csLButtonDown);
end;
end// 下面一行有点特别。如果您仔细的话会看到这个消息是CM_VISIBLECHANGED.// 而不是我们熟悉的WM_开头的标准Windows消息.// 尽管Borland没有在它的帮助中提到有这一类的CM消息存在。但很显然这是BCB的// 自定义消息。呵呵，如果您对此有兴趣可以在VCL源码中查找相关的内容。一定会有不小的收获。
else if Message.Msg = CM_VISIBLECHANGED then
with Message do
SendDockNotification(Msg, WParam, LParam);// 最后调用dispatch方法。
Dispatch(Message);end;
看完这段代码，你会发现TControl类实际上只处理了鼠标消息，没有处理的消息最后都转入Dispatch()来处理。
但这里需要强调指出的是TControl自己并没有获得焦点Focus的能力。TControl的子类TWinControl才具有这样的能力。我凭什么这样讲？呵呵，还是打开BCB的帮助。很多朋友抱怨BCB的帮助实在不如VC的MSDN。毋庸讳言，的确差远了。而且这个帮助还经常有问题。但有总比没有好啊。
言归正传，在帮助的The TWinControl Branch 分支下，您可以看到关于TWinControl类的简介。指出TWinControl类是所有窗体类控件的基类。所谓窗体类控件指的是这样一类控件：
1. 可以在程序运行时取得焦点的控件。
2. 其他的控件可以显示数据，但只有窗体类控件才能和用户发生键盘交互。
3. 窗体类控件能够包含其他控件(容器)。
4. 包含其他控件的控件又称做父控件。只有窗体类控件才能够作为其他控件的父控件。
5. 窗体类控件拥有句柄。
除了能够接受焦点之外，TWinControl的一切都跟TControl没什么分别。这一点意味着TwinControl可以对许多的标准事件作出响应，Windows也必须为它分配一个句柄。并且与这个主题相关的最重要的是，这里提到是由BCB负责来对控件进行重画以及消息处理。这就是说，TwinControl封装了这一切。
似乎扯的太远了。但我要提出来的问题是TControl类的WndProc方法中处理了鼠标消息。但这个消息只有它的子类TwinControl才能够得到啊!？
这怎么可以呢... Borland是如何实现这一切的呢？这个问题实在很奥妙。为了看个究竟，再次深入VCL吧。
还是在control.pas中，TWinControl继承了TControl的WndProc方法。源码如下：
procedure TWinControl.WndProc(var Message: TMessage);var
Form: TCustomForm;
KeyState: TKeyboardState;
WheelMsg: TCMMouseWheel;begin
case Message.Msg of
WM_SETFOCUS:
begin
Form := GetParentForm(Self);
if (Form <> nil) and not Form.SetFocusedControl(Self) then Exit;
end;
WM_KILLFOCUS:
if csFocusing in ControlState then Exit;
WM_NCHITTEST:
begin
inherited WndProc(Message);
if (Message.Result = HTTRANSPARENT) and (ControlAtPos(ScreenToClient(
SmallPointToPoint(TWMNCHitTest(Message).Pos)), False) <> nil) then
Message.Result := HTCLIENT;
Exit;
end;
WM_MOUSEFIRST..WM_MOUSELAST:
//下面这一句话指出，鼠标消息实际上转入IsControlMouseMsg方法来处理了。
if IsControlMouseMsg(TWMMouse(Message)) then
begin
if Message.Result = 0 then
DefWindowProc(Handle, Message.Msg, Message.wParam, Message.lParam);
Exit;
end;
WM_KEYFIRST..WM_KEYLAST:
if Dragging then Exit;
WM_CANCELMODE:
if (GetCapture = Handle) and (CaptureControl <> nil) and
(CaptureControl.Parent = Self) then
CaptureControl.Perform(WM_CANCELMODE, 0, 0);
else
with Mouse do
if WheelPresent and (RegWheelMessage <> 0) and
(Message.Msg = RegWheelMessage) then
begin
GetKeyboardState(KeyState);
with WheelMsg do
begin
Msg := Message.Msg;
ShiftState := KeyboardStateToShiftState(KeyState);
WheelDelta := Message.WParam;
Pos := TSmallPoint(Message.LParam);
end;
MouseWheelHandler(TMessage(WheelMsg));
Exit;
end;
end;
inherited WndProc(Message);end;
鼠标消息是由IsControlMouseMsg方法来处理的。只有再跟到IsControlMouseMsg去看看啦。源码如下：
function TWinControl.IsControlMouseMsg(var Message: TWMMouse): Boolean;var
//TControl出现啦
Control: TControl;
P: TPoint;begin
if GetCapture = Handle then
begin
Control := nil;
if (CaptureControl <> nil) and (CaptureControl.Parent = Self) then
Control := CaptureControl;
end else
Control := ControlAtPos(SmallPointToPoint(Message.Pos), False);
Result := False;
if Control <> nil then
begin
P.X := Message.XPos - Control.Left;
P.Y := Message.YPos - Control.Top;
file://TControl的Perform方法将消息交由WndProc处理。
Message.Result := Control.Perform(Message.Msg, Message.Keys, Longint(PointToSmallPoint(P)));
Result := True;
二TWinControl.WndProc
procedure TWinControl.WndProc(var Message: TMessage);
var
Form: TCustomForm;
LMouseEvent: TTrackMouseEvent;
P: TPoint;
Target: TControl;
begin
case Message.Msg of
CM_UNTHEMECONTROL:
if (csDesigning in ComponentState) and ThemeServices.ThemesAvailable then
begin
SetWindowTheme(Handle, ' ', ' ');
SetWindowPos(Handle, 0, 0, 0, 0, 0, SWP_NOMOVE or SWP_NOSIZE or SWP_NOZORDER or SWP_NOACTIVATE or SWP_SHOWWINDOW or SWP_FRAMECHANGED);
end;
CM_SETACTIVECONTROL:
begin
Form := GetParentForm(Self);
if (Form <> nil) and (Form <> Self) then
Form.Perform(CM_SETACTIVECONTROL, Message.WParam, Message.LParam);
end;
WM_SETFOCUS:
begin
Form := GetParentForm(Self);
if (Form <> nil) and (not (csDesigning in Form.ComponentState) or (Form.Parent = nil)) then
if not Form.SetFocusedControl(Self) then Exit;
end;
WM_KILLFOCUS:
if csFocusing in ControlState then Exit;
WM_NCHITTEST:
begin
inherited WndProc(Message);
if (Message.Result = HTTRANSPARENT) and (ControlAtPos(ScreenToClient(
SmallPointToPoint(TWMNCHitTest(Message).Pos)), False) <> nil) then
Message.Result := HTCLIENT;
Exit;
end;
WM_MOUSELEAVE:
begin
FMouseInClient := False;
if FMouseControl <> nil then
FMouseControl.Perform(CM_MOUSELEAVE, 0, 0)
else
Perform(CM_MOUSELEAVE, 0, 0);
FMouseControl := nil;
end;
WM_MOUSEFIRST..WM_MOUSELAST:
begin
if Message.Msg = WM_MOUSEMOVE then
begin
P := ClientToScreen(Point(TWMMouse(Message).XPos, TWMMouse(Message).YPos));
CaptureControl := GetCaptureControl;
if CaptureControl = nil then
Target := FindDragTarget(P, True)
else
Target := CaptureControl;
if (FMouseControl <> Target) then
begin
if ((FMouseControl <> nil) and (CaptureControl = nil)) or
((CaptureControl <> nil) and (FMouseControl = CaptureControl)) or
((CaptureControl is TControl) and (CaptureControl.Parent = FMouseControl)) then
FMouseControl.Perform(CM_MOUSELEAVE, 0, 0);
if FMouseControl <> nil then
FMouseControl.RemoveFreeNotification(Self);
FMouseControl := Target;
if FMouseControl <> nil then
FMouseControl.FreeNotification(Self);
if ((FMouseControl <> nil) and (CaptureControl = nil)) or
((CaptureControl <> nil) and (FMouseControl = CaptureControl)) then
FMouseControl.Perform(CM_MOUSEENTER, 0, 0);
end;
if not FMouseInClient then
begin
FMouseInClient := True;
// Register for a WM_MOUSELEAVE message which ensures CM_MOUSELEAVE
// is called when the mouse leaves the TWinControl
LMouseEvent.cbSize := SizeOf(LMouseEvent);
LMouseEvent.dwFlags := TME_LEAVE;
LMouseEvent.hwndTrack := Handle;
LMouseEvent.dwHoverTime := HOVER_DEFAULT;
_TrackMouseEvent(@LMouseEvent);
end;
end;
if IsControlMouseMsg(TWMMouse(Message)) then
begin
{ Check HandleAllocated because IsControlMouseMsg might have freed the
window if user code executed something like Parent := nil. }
if (Message.Result = 0) and HandleAllocated then
DefWindowProc(Handle, Message.Msg, Message.wParam, Message.lParam);
Exit;
end;
end;
WM_MOUSEACTIVATE:
if IsControlActivateMsg(TWMMouseActivate(Message)) then
begin
if (Message.Result = 0) and HandleAllocated then
inherited WndProc(Message);
Exit;
end;
WM_KEYFIRST..WM_KEYLAST:
if Dragging then Exit;
WM_CANCELMODE:
if (GetCapture = Handle) and (CaptureControl <> nil) and
(CaptureControl.Parent = Self) then
CaptureControl.Perform(WM_CANCELMODE, 0, 0);
CM_DESTROYHANDLE:
begin
if Boolean(Message.WParam) then // Sender has csRecreating set
UpdateRecreatingFlag(True);
try
DestroyHandle;
finally
if Boolean(Message.WParam) then
UpdateRecreatingFlag(False);
end;
Exit;
end;
end;
inherited WndProc(Message);
if Message.Msg = WM_UPDATEUISTATE then
Invalidate; // Ensure control is repainted
end;
三TControl.WndProc
end;end;
procedure TControl.WndProc(var Message: TMessage);
var
Form: TCustomForm;
begin
if (csDesigning in ComponentState) then
begin
Form := GetParentForm(Self);
if (Form <> nil) and (Form.Designer <> nil) and
Form.Designer.IsDesignMsg(Self, Message) then Exit;
end
else if (Message.Msg >= WM_KEYFIRST) and (Message.Msg <= WM_KEYLAST) then
begin
Form := GetParentForm(Self);
if (Form <> nil) and Form.WantChildKey(Self, Message) then Exit;
end
else if (Message.Msg >= WM_MOUSEFIRST) and (Message.Msg <= WM_MOUSELAST) then
begin
if not (csDoubleClicks in ControlStyle) then
case Message.Msg of
WM_LBUTTONDBLCLK, WM_RBUTTONDBLCLK, WM_MBUTTONDBLCLK:
Dec(Message.Msg, WM_LBUTTONDBLCLK - WM_LBUTTONDOWN);
end;
case Message.Msg of
WM_MOUSEMOVE: Application.HintMouseMessage(Self, Message);
WM_LBUTTONDOWN, WM_LBUTTONDBLCLK:
begin
if FDragMode = dmAutomatic then
begin
BeginAutoDrag;
Exit;
end;
Include(FControlState, csLButtonDown);
end;
WM_LBUTTONUP:
Exclude(FControlState, csLButtonDown);
end;
end
else if Message.Msg = CM_VISIBLECHANGED then
with Message do
SendDockNotification(Msg, WParam, LParam);
Dispatch(Message);
end;
2012-12-25 19:54未知admin
.
关键字：
重载TControl的WndProc方法
还是先谈谈VCL的继承策略。VCL中的继承链的顶部是TObject基类。一切的VCL组件和对象都继承自TObject。
打开BCB帮助查看TControl的继承关系：
TObject->TPersistent->TComponent->TControl
呵呵，原来TControl是从TPersistent类的子类TComponent类继承而来的。TPersistent抽象基类具有使用流stream来存取类的属性的能力。
TComponent类则是所有VCL组件的父类。
这就是所有的VCL组件包括您的自定义组件可以使用dfm文件存取属性的原因『当然要是TPersistent的子类，我想您很少需要直接从TObject类来派生您的自定义组件吧』。
TControl类的重要性并不亚于它的父类们。在BCB的继承关系中，TControl类的是所有VCL可视化组件的父类。实际上就是控件的意思吧。所谓可视化是指您可以在运行期间看到和操纵的控件。这类控件所具有的一些基本属性和方法都在TControl类中进行定义。
TControl的实现在BorlandCBuilder5SourceVclcontrol.pas中可以找到。『可能会有朋友问你怎么知道在那里？使用BCB提供的Search -> Find in files很容易找到。或者使用第三方插件的grep功能。』
好了，进入VCL的源码吧。说到这里免不了要抱怨一下Borland。哎，为什么要用pascal实现这一切.....:-(
TControl继承但并没有重写TObject的Dispatch()方法。反而提供了一个新的方法就是xycleo提到的WndProc()。一起来看看Borland的工程师们是怎么写的吧。
procedure TControl.WndProc(var Message: TMessage);var
Form: TCustomForm;begin//由拥有control的窗体来处理设计期间的消息
if (csDesigning in ComponentState) then
begin
Form := GetParentForm(Self);
if (Form <> nil) and (Form.Designer <> nil) and
Form.Designer.IsDesignMsg(Self, Message) then Exit;
end//如果需要，键盘消息交由拥有control的窗体来处理
else if (Message.Msg >= WM_KEYFIRST) and (Message.Msg <= WM_KEYLAST) then
begin
Form := GetParentForm(Self);
if (Form <> nil) and Form.WantChildKey(Self, Message) then Exit;
end//处理鼠标消息
else if (Message.Msg >= WM_MOUSEFIRST) and (Message.Msg <= WM_MOUSELAST) then
begin
if not (csDoubleClicks in ControlStyle) then
case Message.Msg of
WM_LBUTTONDBLCLK, WM_RBUTTONDBLCLK, WM_MBUTTONDBLCLK:
Dec(Message.Msg, WM_LBUTTONDBLCLK - WM_LBUTTONDOWN);
end;
case Message.Msg of
WM_MOUSEMOVE: Application.HintMouseMessage(Self, Message);
WM_LBUTTONDOWN, WM_LBUTTONDBLCLK:
begin
if FDragMode = dmAutomatic then
begin
BeginAutoDrag;
Exit;
end;
Include(FControlState, csLButtonDown);
end;
WM_LBUTTONUP:
Exclude(FControlState, csLButtonDown);
end;
end// 下面一行有点特别。如果您仔细的话会看到这个消息是CM_VISIBLECHANGED.// 而不是我们熟悉的WM_开头的标准Windows消息.// 尽管Borland没有在它的帮助中提到有这一类的CM消息存在。但很显然这是BCB的// 自定义消息。呵呵，如果您对此有兴趣可以在VCL源码中查找相关的内容。一定会有不小的收获。
else if Message.Msg = CM_VISIBLECHANGED then
with Message do
SendDockNotification(Msg, WParam, LParam);// 最后调用dispatch方法。
Dispatch(Message);end;
看完这段代码，你会发现TControl类实际上只处理了鼠标消息，没有处理的消息最后都转入Dispatch()来处理。
但这里需要强调指出的是TControl自己并没有获得焦点Focus的能力。TControl的子类TWinControl才具有这样的能力。我凭什么这样讲？呵呵，还是打开BCB的帮助。很多朋友抱怨BCB的帮助实在不如VC的MSDN。毋庸讳言，的确差远了。而且这个帮助还经常有问题。但有总比没有好啊。
言归正传，在帮助的The TWinControl Branch 分支下，您可以看到关于TWinControl类的简介。指出TWinControl类是所有窗体类控件的基类。所谓窗体类控件指的是这样一类控件：
1. 可以在程序运行时取得焦点的控件。
2. 其他的控件可以显示数据，但只有窗体类控件才能和用户发生键盘交互。
3. 窗体类控件能够包含其他控件(容器)。
4. 包含其他控件的控件又称做父控件。只有窗体类控件才能够作为其他控件的父控件。
5. 窗体类控件拥有句柄。
除了能够接受焦点之外，TWinControl的一切都跟TControl没什么分别。这一点意味着TwinControl可以对许多的标准事件作出响应，Windows也必须为它分配一个句柄。并且与这个主题相关的最重要的是，这里提到是由BCB负责来对控件进行重画以及消息处理。这就是说，TwinControl封装了这一切。
似乎扯的太远了。但我要提出来的问题是TControl类的WndProc方法中处理了鼠标消息。但这个消息只有它的子类TwinControl才能够得到啊!？
这怎么可以呢... Borland是如何实现这一切的呢？这个问题实在很奥妙。为了看个究竟，再次深入VCL吧。
还是在control.pas中，TWinControl继承了TControl的WndProc方法。源码如下：
procedure TWinControl.WndProc(var Message: TMessage);var
Form: TCustomForm;
KeyState: TKeyboardState;
WheelMsg: TCMMouseWheel;begin
case Message.Msg of
WM_SETFOCUS:
begin
Form := GetParentForm(Self);
if (Form <> nil) and not Form.SetFocusedControl(Self) then Exit;
end;
WM_KILLFOCUS:
if csFocusing in ControlState then Exit;
WM_NCHITTEST:
begin
inherited WndProc(Message);
if (Message.Result = HTTRANSPARENT) and (ControlAtPos(ScreenToClient(
SmallPointToPoint(TWMNCHitTest(Message).Pos)), False) <> nil) then
Message.Result := HTCLIENT;
Exit;
end;
WM_MOUSEFIRST..WM_MOUSELAST:
//下面这一句话指出，鼠标消息实际上转入IsControlMouseMsg方法来处理了。
if IsControlMouseMsg(TWMMouse(Message)) then
begin
if Message.Result = 0 then
DefWindowProc(Handle, Message.Msg, Message.wParam, Message.lParam);
Exit;
end;
WM_KEYFIRST..WM_KEYLAST:
if Dragging then Exit;
WM_CANCELMODE:
if (GetCapture = Handle) and (CaptureControl <> nil) and
(CaptureControl.Parent = Self) then
CaptureControl.Perform(WM_CANCELMODE, 0, 0);
else
with Mouse do
if WheelPresent and (RegWheelMessage <> 0) and
(Message.Msg = RegWheelMessage) then
begin
GetKeyboardState(KeyState);
with WheelMsg do
begin
Msg := Message.Msg;
ShiftState := KeyboardStateToShiftState(KeyState);
WheelDelta := Message.WParam;
Pos := TSmallPoint(Message.LParam);
end;
MouseWheelHandler(TMessage(WheelMsg));
Exit;
end;
end;
inherited WndProc(Message);end;
鼠标消息是由IsControlMouseMsg方法来处理的。只有再跟到IsControlMouseMsg去看看啦。源码如下：
function TWinControl.IsControlMouseMsg(var Message: TWMMouse): Boolean;var
//TControl出现啦
Control: TControl;
P: TPoint;begin
if GetCapture = Handle then
begin
Control := nil;
if (CaptureControl <> nil) and (CaptureControl.Parent = Self) then
Control := CaptureControl;
end else
Control := ControlAtPos(SmallPointToPoint(Message.Pos), False);
Result := False;
if Control <> nil then
begin
P.X := Message.XPos - Control.Left;
P.Y := Message.YPos - Control.Top;
file://TControl的Perform方法将消息交由WndProc处理。
Message.Result := Control.Perform(Message.Msg, Message.Keys, Longint(PointToSmallPoint(P)));
Result := True;
二TWinControl.WndProc
procedure TWinControl.WndProc(var Message: TMessage);
var
Form: TCustomForm;
LMouseEvent: TTrackMouseEvent;
P: TPoint;
Target: TControl;
begin
case Message.Msg of
CM_UNTHEMECONTROL:
if (csDesigning in ComponentState) and ThemeServices.ThemesAvailable then
begin
SetWindowTheme(Handle, ' ', ' ');
SetWindowPos(Handle, 0, 0, 0, 0, 0, SWP_NOMOVE or SWP_NOSIZE or SWP_NOZORDER or SWP_NOACTIVATE or SWP_SHOWWINDOW or SWP_FRAMECHANGED);
end;
CM_SETACTIVECONTROL:
begin
Form := GetParentForm(Self);
if (Form <> nil) and (Form <> Self) then
Form.Perform(CM_SETACTIVECONTROL, Message.WParam, Message.LParam);
end;
WM_SETFOCUS:
begin
Form := GetParentForm(Self);
if (Form <> nil) and (not (csDesigning in Form.ComponentState) or (Form.Parent = nil)) then
if not Form.SetFocusedControl(Self) then Exit;
end;
WM_KILLFOCUS:
if csFocusing in ControlState then Exit;
WM_NCHITTEST:
begin
inherited WndProc(Message);
if (Message.Result = HTTRANSPARENT) and (ControlAtPos(ScreenToClient(
SmallPointToPoint(TWMNCHitTest(Message).Pos)), False) <> nil) then
Message.Result := HTCLIENT;
Exit;
end;
WM_MOUSELEAVE:
begin
FMouseInClient := False;
if FMouseControl <> nil then
FMouseControl.Perform(CM_MOUSELEAVE, 0, 0)
else
Perform(CM_MOUSELEAVE, 0, 0);
FMouseControl := nil;
end;
WM_MOUSEFIRST..WM_MOUSELAST:
begin
if Message.Msg = WM_MOUSEMOVE then
begin
P := ClientToScreen(Point(TWMMouse(Message).XPos, TWMMouse(Message).YPos));
CaptureControl := GetCaptureControl;
if CaptureControl = nil then
Target := FindDragTarget(P, True)
else
Target := CaptureControl;
if (FMouseControl <> Target) then
begin
if ((FMouseControl <> nil) and (CaptureControl = nil)) or
((CaptureControl <> nil) and (FMouseControl = CaptureControl)) or
((CaptureControl is TControl) and (CaptureControl.Parent = FMouseControl)) then
FMouseControl.Perform(CM_MOUSELEAVE, 0, 0);
if FMouseControl <> nil then
FMouseControl.RemoveFreeNotification(Self);
FMouseControl := Target;
if FMouseControl <> nil then
FMouseControl.FreeNotification(Self);
if ((FMouseControl <> nil) and (CaptureControl = nil)) or
((CaptureControl <> nil) and (FMouseControl = CaptureControl)) then
FMouseControl.Perform(CM_MOUSEENTER, 0, 0);
end;
if not FMouseInClient then
begin
FMouseInClient := True;
// Register for a WM_MOUSELEAVE message which ensures CM_MOUSELEAVE
// is called when the mouse leaves the TWinControl
LMouseEvent.cbSize := SizeOf(LMouseEvent);
LMouseEvent.dwFlags := TME_LEAVE;
LMouseEvent.hwndTrack := Handle;
LMouseEvent.dwHoverTime := HOVER_DEFAULT;
_TrackMouseEvent(@LMouseEvent);
end;
end;
if IsControlMouseMsg(TWMMouse(Message)) then
begin
{ Check HandleAllocated because IsControlMouseMsg might have freed the
window if user code executed something like Parent := nil. }
if (Message.Result = 0) and HandleAllocated then
DefWindowProc(Handle, Message.Msg, Message.wParam, Message.lParam);
Exit;
end;
end;
WM_MOUSEACTIVATE:
if IsControlActivateMsg(TWMMouseActivate(Message)) then
begin
if (Message.Result = 0) and HandleAllocated then
inherited WndProc(Message);
Exit;
end;
WM_KEYFIRST..WM_KEYLAST:
if Dragging then Exit;
WM_CANCELMODE:
if (GetCapture = Handle) and (CaptureControl <> nil) and
(CaptureControl.Parent = Self) then
CaptureControl.Perform(WM_CANCELMODE, 0, 0);
CM_DESTROYHANDLE:
begin
if Boolean(Message.WParam) then // Sender has csRecreating set
UpdateRecreatingFlag(True);
try
DestroyHandle;
finally
if Boolean(Message.WParam) then
UpdateRecreatingFlag(False);
end;
Exit;
end;
end;
inherited WndProc(Message);
if Message.Msg = WM_UPDATEUISTATE then
Invalidate; // Ensure control is repainted
end;
三TControl.WndProc
end;end;
procedure TControl.WndProc(var Message: TMessage);
var
Form: TCustomForm;
begin
if (csDesigning in ComponentState) then
begin
Form := GetParentForm(Self);
if (Form <> nil) and (Form.Designer <> nil) and
Form.Designer.IsDesignMsg(Self, Message) then Exit;
end
else if (Message.Msg >= WM_KEYFIRST) and (Message.Msg <= WM_KEYLAST) then
begin
Form := GetParentForm(Self);
if (Form <> nil) and Form.WantChildKey(Self, Message) then Exit;
end
else if (Message.Msg >= WM_MOUSEFIRST) and (Message.Msg <= WM_MOUSELAST) then
begin
if not (csDoubleClicks in ControlStyle) then
case Message.Msg of
WM_LBUTTONDBLCLK, WM_RBUTTONDBLCLK, WM_MBUTTONDBLCLK:
Dec(Message.Msg, WM_LBUTTONDBLCLK - WM_LBUTTONDOWN);
end;
case Message.Msg of
WM_MOUSEMOVE: Application.HintMouseMessage(Self, Message);
WM_LBUTTONDOWN, WM_LBUTTONDBLCLK:
begin
if FDragMode = dmAutomatic then
begin
BeginAutoDrag;
Exit;
end;
Include(FControlState, csLButtonDown);
end;
WM_LBUTTONUP:
Exclude(FControlState, csLButtonDown);
end;
end
else if Message.Msg = CM_VISIBLECHANGED then
with Message do
SendDockNotification(Msg, WParam, LParam);
Dispatch(Message);
end;
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