CustomTrack

Qualified name: delphifmx.CustomTrack

class CustomTrack

Bases: StyledControl

Base class for all track bar components. TCustomTrack is the base class for all track bar components such as TTrackBar. If you need to create your own custom track bar, then you should derive your component from TCustomTrack, as it already implements functionality for drawing and manipulating the track bar.

Methods

AfterConstruction	Responds after the last constructor has executed and loads the control presentation.
ApplyStyleLookup	Gets and applies the style of a TStyledControl.
ApplyTriggerEffect	Applies the specified mouse trigger effect to all the children of this FMX object that are of type TEffect.
BeforeDestruction	Performs any necessary actions before the first destructor is called.
FindStyleResource	Finds the linked resource object for the style specified by name.
HasPresentationProxy
Inflate	Call this procedure to get and apply its style lookup.
LoadPresentation
NeedStyleLookup	Call this procedure to indicate that this control requires to get and apply its style lookup.
PointInObjectLocal	Checks whether the point specified by local coordinates belongs to the control area.
RecalcEnabled	Forces the current control to recalculate its enabled state.
RecalcOpacity	Forces the current control to recalculate its Opacity property.
ReloadPresentation
StartTriggerAnimation	Embarcadero Technologies does not currently have any additional information.
StartTriggerAnimationWait	Embarcadero Technologies does not currently have any additional information.
UnloadPresentation

Attributes

AbsoluteClipRect	Specifies the absolute rectangle of the control after all its parent controls clip it.
AbsoluteEnabled	Specifies whether the control is absolutely enabled.
AbsoluteHeight	Specifies the absolute height of the control.
AbsoluteMatrix	Specifies the absolute transformation matrix of the control.
AbsoluteOpacity	Specifies the absolute opacity of the control.
AbsoluteRect	Specifies the absolute rectangle that bounds the control.
AbsoluteScale	Specifies the absolute scale of the control.
AbsoluteWidth	Specifies the absolute width of the control.
ActionClient	Specifies whether the component object has an associated action.
AdjustSizeValue	Updates the width and height of this control according to its current style
AdjustType	Determines if and how the width and height of this control should be modified to take the fixed space dictated by the style of this control
Align	Specifies the alignment options (top, left, client, and so on) of this control.
Anchors	Specifies how the control is anchored to its parent.
ApplyingEffect	A flag that signals when a control is in the process of applying an effect.
AutoCapture	Specifies whether the control captures mouse events.
AutoTranslate	Specifies whether the control's text should be translated
AxisAlignedRect	A TRectF defined by the width and height of the control.
BoundsRect	Specifies the bounding rectangle of the control.
CanParentFocus	Specifies whether the parent of this control should be evaluated to receive focus.
Canvas	Provides the drawing surface of the control.
Children	Stores an array of children attached to this parent component.
ChildrenCount	Read-only property that specifies the number of children in the children list.
ChildrenRect	Specifies the bigger rectangle area occupied by parent and children controls.
ClassName	Returns the TObject.ClassName
ClipChildren	Specifies if children of the control should be clipped to the control's on-screen region.
ClipParent	Specifies whether the current control has clipped its parent.
ClipRect	Specifies the bound rectangle to be clipped.
ComObject	Specifies the interface reference implemented by the component.
ComponentCount	Returns the owned component count
ComponentIndex	Indicates the position of the component in its owner's Components property array.
ComponentState	Describes the current state of the component, indicating when a component needs to avoid certain actions.
ComponentStyle	Governs the behavior of the component.
Components	Returns an iterator over the owned components
ControlType	ControlType:
Controls	Returns an iterator over contained controls
ControlsCount	Returns the count of contained controls
Cursor	Image to use to represent the mouse pointer when it passes into the region covered by the control.
Data	Stores a Tvalue, which is a data structure that can store different kinds of data types.
DefaultSize	Embarcadero Technologies does not currently have any additional information.
DefaultStyleLookupName	Returns a string with the name of the default style of this control
DesignInfo	Contains information used by the Form designer.
DisableDisappear	Embarcadero Technologies does not currently have any additional information.
DisableFocusEffect	Specifies whether the control has the focus effect disabled.
DragMode	Specifies how the control initiates drag-and-drop operations.
EnableDragHighlight	Specifies whether the control is highlighted when the dragged object is over it.
Enabled	Specifies whether the control responds to mouse, keyboard, and timer events.
FixedSize	Embarcadero Technologies does not currently have any additional information.
Frequency	Specifies the number of positions the slider advances with each move.
HasAfterPaintEffect	Specifies whether the control has an effect that is applied after the control is painted.
HasClipParent	Control that is a direct child of this control and has clipped this control.
HasDisablePaintEffect	Specifies whether the control's effect is painted.
HasEffect	Specifies whether the control has an applied effect.
Height	Height specifies the vertical size of the control (in dp).
HelpContext	Contains the numeric context ID that identifies the Help topic for the control.
HelpKeyword	Contains the keyword string that identifies the Help topic for the control.
HelpType	Specifies whether the control's context-sensitive Help topic is identified by a context ID or by keyword.
Hint	Specifies the text string that appears when the user moves the mouse over a control.
HitTest	Enables the control to capture mouse events.
InPaintTo	Specifies whether the control is currently being painted.
Index	Specifies the index of the child object in the children array attached to this object.
InheritedCursor	Image used to represent the mouse pointer when it passes into the region covered by the control.
InvertAbsoluteMatrix	Specifies the inverse matrix of AbsoluteMatrix.
IsDragOver	Specifies whether a dragged object is over the area of the current control.
IsFocused	Determines whether the control has input focus.
IsInflated	Whether the current style of this control has been actually applied to the control.
IsMouseOver	Specifies whether the mouse cursor is over the control.
IsTracking	Indicates whether the Thumb that is associated with this TCustomTrack is pressed.
IsVisible	Specifies whether the control is visible.
LocalRect	Specifies the local rectangle for painting the control.
Locked	Specifies whether the control is locked at design time.
Margins	Aligns the component to the margins points of other components.
Max	Specifies the maximum value of this track bar for the maximum position of the slider.
Min	Specifies the minimum value of this track bar, for the minimum position of the slider.
Model	DataModel:
Name	Specifies the name of the component as referenced in code.
Observers	Indicates the TObservers object added to the TComponent.
OnGesture	Callable[[Object, GestureEventInfo, bool], None]:
Opacity	Specifies the control opacity.
Orientation	Specifies the orientation of this track bar (from left to right or from bottom to top).
Owner	Returns the Component Owner
Padding	Aligns the component to the padding points of other components.
Parent	Returns/Sets the Control Visibility
ParentClassStyleLookupName	The name of the default style of the parent class of this control.
ParentControl	Specifies the parent control of this control.
ParentedRect	Specifies the bounding rectangle of the control within its parent.
ParentedVisible	Specifies whether all the control's parents are visible.
PopupMenu	Specifies the context (pop-up) menu object.
Position	Returns an access to the position of the control inside its parent
Presentation	Object:
PresentationProxy	PresentationProxy:
PresentationState	PresentationState:
Pressed	Indicates whether the control is currently pressed.
PressedPosition	A point that indicates where exactly on the control the click occured.
Root	Specifies the root parent of this object.
Scene	Specifies the current scene in which the control is drawn.
ShowHint	Specifies whether the Hint can be shown.
Size	Specifies the vertical and horizontal size (Size.Height and Size.Width) of the control (in pixels).
SmallChange	Controls the number of positions that the Thumb of the TCustomTrack moves each time the user presses on a free area.
Stored	Specifies whether this object is stored in the .XFM file.
StyleLookup	Specifies the name of the resource object to which the current TStyledControl is linked
StyleName	Specifies the style name for this FMX component.
StyleState	This property allows you to define the current state of style
StylesData	Value:
TabOrder	Indicates the position of the control in its parent's tab order.
TabStop	Embarcadero Technologies does not currently have any additional information.
Tag	Stores a NativeInt integral value as a part of a component.
TagFloat	Custom property that stores any floating-point value.
TagObject	Custom property that stores any object value.
TagString	Custom property that stores any string value.
Thumb	The part of a track bar that you move to change the value of the track bar.
Touch	Specifies the touch manager component associated with the control.
TouchTargetExpansion	Set of optional pixel values you can specify to expand the touch target of a FireMonkey styled control.
Tracking	Indicates whether thumb tracking is active or not.
UpdateRect	Specifies the rectangle area of the control that needs to be updated.
VCLComObject	Represents information used internally by components that support COM.
Value	Specifies the current value of this track bar.
ValueRange	Provides access to the Value value, to its Min and Max boundaries, and to the Frequency and ViewportSize properties.
ViewportSize	Specifies the size, in pixels, of the area that the slider cannot span to the left or right of this track bar.
Visible	Returns/Sets the Control Visibility
Width	Specifies the horizontal size of the control (in pixels).

AdjustSizeValue

Updates the width and height of this control according to its current style

AdjustType

Determines if and how the width and height of this control should be modified to take the fixed space dictated by the style of this control

AfterConstruction()

Responds after the last constructor has executed and loads the control presentation. FMX.StdCtrls.TCustomTrack.AfterConstruction inherits from FMX.Controls.Presentation.TPresentedControl.AfterConstruction. All content below this line refers to FMX.Controls.Presentation.TPresentedControl.AfterConstruction. Responds after the last constructor has executed and loads the control presentation. AfterConstruction is called automatically after the object’s last constructor has executed. Do not call it explicitly in your applications.

ApplyStyleLookup()

Gets and applies the style of a TStyledControl.

ApplyTriggerEffect(AInstance: FmxObject, ATrigger: str) → None

Applies the specified mouse trigger effect to all the children of this FMX object that are of type TEffect. ApplyTriggerEffect iterates through all the children of this FMX object and, if one of them is of type TEffect, applies the mouse trigger given through the ATrigger parameter (which can be ‘IsMouseOver’, ‘IsMouseOver’, ‘IsDragOver’, and so on). AInstance specifies the instance of the FMX object to which the trigger effect is applied.

AutoTranslate

Specifies whether the control’s text should be translated

BeforeDestruction()

Performs any necessary actions before the first destructor is called. FMX.Controls.TStyledControl.BeforeDestruction inherits from System.Classes.TComponent.BeforeDestruction. All content below this line refers to System.Classes.TComponent.BeforeDestruction. Performs any necessary actions before the first destructor is called. BeforeDestruction is called automatically immediately before the component’s first destructor executes. Do not call it explicitly in your applications. As implemented in TComponent, BeforeDestruction checks whether the Destroying method has been called, and if not, calls it. Descendants that override this method to perform other actions before a component is destroyed should call the inherited method first to ensure that this check takes place.

ControlType

ControlType:

DefaultStyleLookupName

Returns a string with the name of the default style of this control

FindStyleResource(AStyleLookup: str, AClone: bool) → FmxObject

Finds the linked resource object for the style specified by name. The AStyleLookup parameter specifies the name of the style. If AStyleLookup is empty, FindStyleResource returns nil. If no resource object is linked directly to the control, FindStyleResource looks to the styles of the control’s children. If no resource object is found, it returns nil. Clone determines whether the returned style resource object should be the original style object (False) or a copy of the original (True). Finds the linked resource object for the style specified by name. The AStyleLookup parameter specifies the name of the style. If AStyleLookup is empty, FindStyleResource returns nil. If no resource object is linked directly to the control, FindStyleResource looks to the styles of the control’s children. If no resource object is found, it returns nil. Clone determines whether the returned style resource object should be the original style object (False) or a copy of the original (True).

Frequency

Specifies the number of positions the slider advances with each move. Use the Frequency property to specify how many steps at once the slider advances with each move. For instance, if you set Frequency to 10, Min to 0, and Max to 100, then there are only 10 steps for this slider to move within the 0 to 100 range; Value is incremented or decremented with 10 divisions. Frequency is a floating-point Single value; setting Frequency to 0 enables this track bar to increment or decrement by 0.01 divisions by step. Setting Frequency to any integer value (for instance 1, or 5, and so on) will enable this track bar to increment or decrement by the specified value. However, please take into consideration that if you set Frequency to any value greater than 0 and you try to programmatically assign a value to Value, then your value will be converted to the nearest multiple of Frequency. For instance, setting Frequency to 5 and then attempting to programmatically set Value to 12 will actually set Value to 10.

MyTrackBar.Frequency := 5; MyTrackBar.Value := 12; { actually sets Value to 10 }

MyTrackBar->Frequency = 5; MyTrackBar->Value = 12; /* actually sets Value to 10 */

Type:

float

HasPresentationProxy() → Boolean

Inflate()

Call this procedure to get and apply its style lookup.

IsTracking

Indicates whether the Thumb that is associated with this TCustomTrack is pressed. This is a read-only property. The following table shows the value of IsTracking in some common scenarios:

Tracking

Scenario

Behaviour

Events fired

IsTracking

True or False

Press an arrow key on the keyboard.

The Thumb moves for one “step”.

OnTracking OnChange

False

True

Click on the Thumb of the track bar and move the Thumb.

The Thumb moves as much as you move it.

For each “step” of the movement:

OnTracking OnChange

True

False

Click on the Thumb of the track bar and move the Thumb.

The Thumb moves as much as you move it.

For each step of the movement:

OnTracking After you release the Thumb

OnChange

True

True

Click anywhere on the track bar (excluding the Thumb).

The Thumb moves for one “step”.

OnTracking OnChange

False

False

Click anywhere on the track bar (excluding the Thumb).

The Thumb moves to the position where you click.

OnTracking OnChange

False

True or False

Hold the Shift button and click anywhere on the track bar (excluding the Thumb).

The Thumb moves to the position where you click.

OnTracking OnChange

False

Type:

bool

LoadPresentation()

Max

Specifies the maximum value of this track bar for the maximum position of the slider. Use the Max property to set a maximum value up to which the slider of this track bar can go. For instance, if Max is set to 100 (a default value), then attempting to move the slider to the maximum will result in a Value of 100.

Type:

float

Min

Specifies the minimum value of this track bar, for the minimum position of the slider. Use the Min property to set a minimum value down to which the slider of this track bar can go. For instance, if Min is set to 0 (a default value), then attempting to move the slider to the minimum will result in a Value of 0.

Type:

float

Model

DataModel:

NeedStyleLookup()

Call this procedure to indicate that this control requires to get and apply its style lookup.

Orientation

Specifies the orientation of this track bar (from left to right or from bottom to top). Use the Orientation property to specify how this track bar will be displayed in terms of left-to-right orientation or bottom-to-top orientation. Orientation can have one of the following values:

Value

Meaning

Vertical

The track bar is rendered with the bottom-to-top orientation.

Horizontal

The track bar is rendered with the left-to-right orientation.

Type:

Orientation

PointInObjectLocal(X: float, Y: float) → bool

Checks whether the point specified by local coordinates belongs to the control area. PointInObjectLocal returns True if the specified point belongs to the control area, and False otherwise. The X and Y are the local coordinates of the point to be checked (compare with PointInObject):

X is the X coordinate. Y is the Y coordinate. The local coordinates of the upper-left corner of the control rectangle are (0,0), and the local coordinates of the lower-right corner are (Width, Height). The points of the control boundary specified by BoundsRect belong to the control and PointInObjectLocal returns True for them. If a control supports the Touch property, the control area can be optionally inflated on the values specified by the TouchTargetExpansion property. TouchTargetExpansion keeps four optional parameters representing the expansion for the four sides of the control in pixels (Bottom, Left, Right, and Top). The dclasses can change the ‘control area’ definition. For example:

The FMX.Objects.TSelection class extends the ‘control area’ definition relative to BoundsRect. FMX.Objects.TSelection.PointInObjectLocal also returns True if the point belongs to any of small rectangles of the four grip controls used to manage the selection shape. The rectangles of the grip controls are rectangles surrounding the four corners of the TSelection rectangle. The Width and Height of these rectangles are equal to 2 * GripSize. For example, the grip control’s rectangle of the upper-right corner UR_Corner of TSelection is defined by the following corners: (UR_Corner.Top - GripSize, UR_Corner.Right - GripSize)–upper-left corner of the grip. (UR_Corner.Top + GripSize, UR_Corner.Right + GripSize)–lower-right corner of the grip. FMX.Objects.TSelectionPoint.PointInObjectLocal returns True if the specified point belongs to the rectangle of the grip control corresponding to the TSelectionPoint object, and False otherwise.

Presentation

Object:

PresentationProxy

PresentationProxy:

PresentationState

PresentationState:

RecalcEnabled()

Forces the current control to recalculate its enabled state. RecalcEnabled also forces the control’s children to recalculate their enabled state.

RecalcOpacity()

Forces the current control to recalculate its Opacity property. RecalcOpacity also forces the control’s children to recalculate their Opacity property.

ReloadPresentation()

SmallChange

Controls the number of positions that the Thumb of the TCustomTrack moves each time the user presses on a free area.

Type:

float

StartTriggerAnimation(AInstance: FmxObject, ATrigger: str) → None

Embarcadero Technologies does not currently have any additional information.

StartTriggerAnimationWait(AInstance: FmxObject, ATrigger: str) → None

Embarcadero Technologies does not currently have any additional information.

StyleLookup

Specifies the name of the resource object to which the current TStyledControl is linked

StyleState

This property allows you to define the current state of style

Thumb

The part of a track bar that you move to change the value of the track bar. The default appearance of the Thumb depends on the platform:

Windows: The Thumb is a rectangle. OS X: The Thumb is a circle. iOS: The Thumb is a circle. Android: The Thumb is a circle.

Type:

Thumb

Tracking

Indicates whether thumb tracking is active or not. The default value of Tracking is True. The following table shows how the value of Tracking impacts the behavior of a track bar and the related events:

Tracking

Scenario

Behaviour

Events fired

IsTracking

True or False

Press an arrow key on the keyboard.

The Thumb moves for one “step”.

OnTracking OnChange

False

True

Click on the Thumb of the track bar and move the Thumb.

The Thumb moves as much as you move it.

For each “step” of the movement:

OnTracking OnChange

True

False

Click on the Thumb of the track bar and move the Thumb.

The Thumb moves as much as you move it.

For each step of the movement:

OnTracking After you release the Thumb

OnChange

True

True

Click anywhere on the track bar (excluding the Thumb).

The Thumb moves for one “step”.

OnTracking OnChange

False

False

Click anywhere on the track bar (excluding the Thumb).

The Thumb moves to the position where you click.

OnTracking OnChange

False

True or False

Hold the Shift button and click anywhere on the track bar (excluding the Thumb).

The Thumb moves to the position where you click.

OnTracking OnChange

False

Type:

bool

UnloadPresentation()

Value

Specifies the current value of this track bar. Set or get Value to specify or obtain the current value of this track bar. You can set Value programmatically or visually at run time, with any value within the interval delimited by Min and Max.

Type:

float

ValueRange

Provides access to the Value value, to its Min and Max boundaries, and to the Frequency and ViewportSize properties.

Type:

ValueRange

ViewportSize

Specifies the size, in pixels, of the area that the slider cannot span to the left or right of this track bar. Use the ViewportSize property to specify the size of the view port of this track bar, that is, the area, in pixels, that the slider of this track bar cannot span. As an example, the picture below shows two track bars, one with ViewportSize set to 0 and the other with ViewportSize set to 50.

Tip: Changing the ViewportSize property does not affect the limits (Min or Max) or the Value of this track bar.

Type:

float