os::ScrollBar Class Reference
[The Syllable Graphical User Interface API]

Description:

The os::ScrollBar is one object that is used in a lot of other GUI elements.

More...

Inheritance diagram for os::ScrollBar:

List of all members.

Public Member Functions
	ScrollBar (const Rect &cFrame, const String &cName, Message *pcMsg, float vMin=0, float vMax=FLT_MAX, int nOrientation=VERTICAL, uint32 nResizeMask=0)
	libSyllable os::ScrollBar
	~ScrollBar ()
	libSyllable os::ScrollBar
void	SetScrollTarget (View *pcTarget)
	Sets the target that the ScrollBar sends messages to.
View *	GetScrollTarget (void)
	Gets the target that the ScrollBar sends messages to.
virtual void	PostValueChange (const Variant &cNewValue)
virtual void	LabelChanged (const String &cNewLabel)
virtual void	EnableStatusChanged (bool bIsEnabled)
virtual bool	Invoked (Message *pcMessage)
	Intercept outgoing messages.
virtual void	FrameSized (const Point &cDelta)
	Virtual hook called by the system when the view is resized.
virtual void	MouseMove (const Point &cNewPos, int nCode, uint32 nButtons, Message *pcData)
	Hook called by the system when the mouse is moved.
virtual void	MouseDown (const Point &cPosition, uint32 nButtons)
	Hook called by the system when a mouse button is pressed.
virtual void	MouseUp (const Point &cPosition, uint32 nButtons, Message *pcData)
	Hook called by the system when a mouse button is release.
virtual void	KeyDown (const char *pzString, const char *pzRawString, uint32 nQualifiers)
	Hook called by the system when a key is pressed while the view has focus.
virtual void	WheelMoved (const Point &cDelta)
	Hook called by the system when the scroll-wheel is rotated.
virtual void	Activated (bool bIsActive)
	Hook called when the view gain or loose focus.
virtual void	Paint (const Rect &cUpdateRect)
	Called by the system update "damaged" areas of the view.
virtual Point	GetPreferredSize (bool bLargest) const
virtual void	TimerTick (int nID)
	Timer dispatch member.
void	SetSteps (float vSmall, float vBig)
	Sets the steps.
void	GetSteps (float *pvSmall, float *pvBig) const
	Gets the steps.
void	SetMinMax (float vMin, float vMax)
	Sets the minimum/maximum step.
void	SetProportion (float vProp)
	Sets the propotion.
float	GetProportion () const
	Gets the propotion.
Classes
class	Private
	internal More...

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Detailed Description

It adds scrolling to an element.

See also:

Author:

Kurt Skauen ([email protected])

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Constructor & Destructor Documentation

ScrollBar::ScrollBar	(	const Rect &	cFrame,
		const String &	cName,
		Message *	pcMsg,
		float	vMin = 0,
		float	vMax = FLT_MAX,
		int	nOrientation = VERTICAL,
		uint32	nResizeMask = 0
	)

Description:

ScrollBar constructor.

Parameters:

	cFrame	- The size and position of the ScrollBar
	cName	- The name of the ScrollBar.
	pcMsg	- The message for the ScrollBar. Used to pass messages to your element
	vMin	- The minimum tick for the ScrollBar
	vMax	- The maximum tick for the ScrollBar
	nOrientation	- The position of the ScrollBar(use os::VERTICAL or os::HORIZONTAL)
	nResizeMask	- Determines what way the ScrollBar will follow the rest of the window. Default is CF_FOLLOW_LEFT|CF_FOLLOW_TOP.

Author:

Kurt Skauen with modifications by Rick Caudill([email protected])

ScrollBar::~ScrollBar

(

)

Description:

The destructor for the ScrollBar. Just sets the target's scrollbar property to NULL

Author:

Kurt Skauen with modifications by Rick Caudill([email protected])

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Member Function Documentation

void ScrollBar::SetScrollTarget

(

View *

pcTarget

)

Description:

Sets the target that the ScrollBar sends messages to.

Parameters:

pcTarget

- the target os::View

Author:

Kurt Skauen

View * ScrollBar::GetScrollTarget

(

void

)

Description:

Gets the target that the ScrollBar sends messages to.

Author:

Kurt Skauen

void ScrollBar::PostValueChange

(

const Variant &

cNewValue

)

[virtual]

Reimplemented from os::Control.

void ScrollBar::LabelChanged

(

const String &

cNewLabel

)

[virtual]

Reimplemented from os::Control.

void ScrollBar::EnableStatusChanged

(

bool

bIsEnabled

)

[virtual]

Implements os::Control.

bool ScrollBar::Invoked

(

Message *

pcMessage

)

[virtual]

Description:

This member is called from Invoke() just before a message is sendt to the target.

This allow classes that inherits from os::Invoker to add data to or otherwhice modify the message before it is sendt. The message can also be canceled entirely by returning false from this member.

The message passed to Invoked() is a copy of the internal message or the message passed to Invoke() (if any) so any changes made here will not affect the internal message or the message passed to Invoke(). When this method returns the message will imidiatly be sendt to the target and then discarded (unless false is returned in which case the message is simply discarded).

The default implementation of this member does nothing and return true.

Parameters:

pcMessage

Pointer to the message that is about to be sendt. You can do any modification you like to this message (but never delete it).

Returns:

Normally you should return true to indicate that the message should be sendt. You can however return false if you for some reason want to cancel the invokation.

See also:

Invoke(), SetMessage(), SetTarget()

Author:

Kurt Skauen ([email protected])

Reimplemented from os::Control.

void ScrollBar::FrameSized

(

const Point &

cDelta

)

[virtual]

Description:

Overload this member if you need to know when the view is resized.

Note:

This member is called after the view is resized. If you need the old size you can subtract the cDelta calue from the current size.

Parameters:

cDelta

The distance the bottom/right corner was moved relative to the upper/left corner.

See also:

FrameMoved(), SetFrame, ResizeBy(), ResizeTo()

Author:

Kurt Skauen ([email protected])

Reimplemented from os::View.

void ScrollBar::MouseMove	(	const Point &	cNewPos,
		int	nCode,
		uint32	nButtons,
		Message *	pcData
	)			[virtual]

Description:

This member is called from the window thread whenever the mouse is moved above the view or if the view has focus.

Oveload this member if your view need to handle mouse-move events.

The default implementation of this member will call MouseMove() on it's parent view if one exists.

Parameters:

	cNewPos	New mouse position given in the views coordinate system.
	nCode	Enter/exit code. This is MOUSE_ENTERED when the mouse first enter the view, MOUSE_EXITED when the mouse leaves the view, MOUSE_INSIDE whenever the mouse move withing the boundary of the view and MOUSE_OUTSIDE when the mouse move outside the view (will only happen if the view has focus).
	nButtons	Bitmask telling which buttons that are currently pressed. Bit 0 is button 1 (left), bit 1 is button 2 (right), and bit 2 is button 3 (middle), and so on.
	pcData	Pointer to a Message object containing the dragged data if the user is in the middle of a drag and drop operation. Otherwise this pointer is NULL. Look at BeginDrag() for a more detailed description of the drag and drop system.

See also:

MouseDown(), MouseUp(), WheelMoved(), BeginDrag()

Author:

Kurt Skauen ([email protected])

Reimplemented from os::View.

void ScrollBar::MouseDown	(	const Point &	cPosition,
		uint32	nButtons
	)			[virtual]

Description:

This member is called from the window thread whenever a mouse button is clicked above the view. You can overload this member if your view need to know about mouse-down events.

A view will not automatically take focus when clicked so if you want that behaviour you must call MakeFocus() from an overloaded version of this member.

The default implementation of this member will call MouseDown() on it's parent view if one exists.

Parameters:

	cPosition	Mouse position in the views coordinate system at the time the mouse was pressed.
	nButtons	Index of the pressed button. Buttons start at 1 for the left button, 2 for the right button, 3 for the middle button. Additional buttons might be supported by the mouse driver and will then be assigned numbers from 4 and up.

See also:

MouseUp(), MouseMove(), WheelMoved()

Author:

Kurt Skauen ([email protected])

Reimplemented from os::View.

void ScrollBar::MouseUp	(	const Point &	cPosition,
		uint32	nButtons,
		Message *	pcData
	)			[virtual]

Description:

This member is called from the window thread whenever a mouse button is released above the view. You can overload this member if your view need to know about mouse-up events or if your view support drag and drop.

If mouse-up was the result of ending a drag and drop operation the pcData member will point to a Message containing the dragged data. Look at BeginDrag() for a more detailed description of the drag and drop system.

The default implementation of this member will call MouseDown() on it's parent view if one exists.

Parameters:

	cPosition	Mouse position in the views coordinate system at the time the mouse was pressed.
	nButtons	Index of the pressed button. Buttons start at 1 for the left button, 2 for the right button, 3 for the middle button. Additional buttons might be supported by the mouse driver and will then be assigned numbers from 4 and up.
	pcData	Pointer to a Message object containing the dragged data if this mouse-up was the end of a drag and drop operation. If no data was dragged it will be NULL.

See also:

MouseDown(), MouseMove(), WheelMoved()

Author:

Kurt Skauen ([email protected])

Reimplemented from os::View.

void ScrollBar::KeyDown	(	const char *	pzString,
		const char *	pzRawString,
		uint32	nQualifiers
	)			[virtual]

Description:

Overload this member if your view need to handle keyboard input. This member is called to allow the view to handle M_KEY_DOWN messages. The most common members are exctracted from the message and passed as parameters but you might need to obtain the raw message with os::Looper::GetCurrentMessage() and find some members yourself if you the data you needed are not passed in.

For example if you need the raw key-code for the pressed key you will have to lookup the "_raw_key" member from the message.

Parameters:

	pzString	String containing a single UTF-8 encoded character. This is the character generated by the pressed key according to the current keymap accounting for any qualifiers that might be pressed.
	pzRawString	Same as pzString except that the key is converted without accounting for qualifiers. Ie. if 'A' is pressed while pressing <SHIFT> pzString will contain 'A' and pzRawString will contain 'a'.
	nQualifiers	Bitmask describing which qualifiers that was active when the key was pressed.

See also:

KeyUp(), os::Looper::GetCurrentMessage()

Author:

Kurt Skauen ([email protected])

Reimplemented from os::View.

void ScrollBar::WheelMoved

(

const Point &

cDelta

)

[virtual]

Description:

This member is called from the window thread whenever the user rotates the scroll wheel with the mouse pointer above this view.

The default implementation of this member will call WheelMoved() on it's parent view if one exists.

Since:

V0.3.7

Parameters:

cDelta

Delta movement. Normally only the y value is used but it is possible for the mouse driver to also support horizontal scroll wheel functionality. The delta value is normally +/- 1.0 for each "click" on the wheel.

See also:

MouseMove(), MouseDown(), MouseUp()

Author:

Kurt Skauen ([email protected])

Reimplemented from os::View.

void ScrollBar::Activated

(

bool

bIsActive

)

[virtual]

Description:

This is a callback member that can be overloaded by derived classes to learn when the view is activated and when it is deactivated. The bIsActive parameter tell whether the focus was lost or gained.

The view has focus when it is the active view in the active window.

Note:

This is a hook function that is called by the system to notify about an event. You should never call this member yourself.

The window is locked when this member is called.

Parameters:

bIsActive

- true if the view gain and false if it loose focus.

See also:

MakeFocus(), WindowActivated()

Author:

Kurt Skauen ([email protected])

Reimplemented from os::View.

void ScrollBar::Paint

(

const Rect &

cUpdateRect

)

[virtual]

Description:

Note:

Warning:

Parameters:

cUpdateRect

A rectangle enclosing all damaged areas. This is just a rough "worst-case", further fine-grained clipping will be performed by the Application Server to avoid updating non-damaged pixels and make the update as fast and flicker-free as possible.

See also:

Invalidate(), Flush()

Author:

Kurt Skauen ([email protected])

Reimplemented from os::View.

Point ScrollBar::GetPreferredSize

(

bool

bLargest

)

const [virtual]

Reimplemented from os::View.

void ScrollBar::TimerTick

(

int

nID

)

[virtual]

Description:

This member will be called by the looper thread when a timer targeting this handler expires.

When a timer created with os::Looper::AddTimer() expires the looper thread will lock the looper and call this member on the target for the expired timer. If more than one timers are created it is possible to distinguish them by the timer ID that is assigned to the timer with os::Looper::AddTimer() and that is passed to TimerTick() through the nID parameter.

Note:

Never do any lenthy operations in any hook members that are called from the looper thread if the looper is involved with the GUI (for example if the looper is a os::Window). The looper will not be able to dispatch messages until the hook returns so spending a long time in this members will make the GUI feel unresponsive.

Warning:

Parameters:

\return

Error codes:

See also:

Author:

Kurt Skauen ([email protected])

Reimplemented from os::Handler.

void ScrollBar::SetSteps	(	float	vSmall,
		float	vBig
	)

..

Description:

Sets the steps on how much/little the Scrollbar moves

Parameters:

	vSmall	- the new smallest step
	vBig	- the new largest step

Author:

Kurt Skauen

void ScrollBar::GetSteps	(	float *	pvSmall,
		float *	pvBig
	)			const

..

Description:

Gets the steps on how much/little the Scrollbar moves

Parameters:

	pvSmall	- pointer to the smallest step
	pvBig	- pointer to the bigest step

Author:

Kurt Skauen

void ScrollBar::SetMinMax	(	float	vMin,
		float	vMax
	)

..

Description:

Sets the minimum and the maximum step that can be done in one click

Parameters:

	vMin	- the minimum step
	vMax	- the maximum step

Author:

Kurt Skauen

void ScrollBar::SetProportion

(

float

vProp

)

..

Description:

Sets the proportion on how the Scrollbar moves

Parameters:

vProp

- the new proportion

Author:

Kurt Skauen

float ScrollBar::GetProportion

(

)

const

..

Description:

Gets the proportion on how the Scrollbar moves

Author:

Kurt Skauen

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