| Client-Side API Reference > Gauge > wijmo.gauge > LinearGauge Class |
constructor(element: any, options?): LinearGauge
Initializes a new instance of the LinearGauge class.
The DOM element that will host the control, or a selector for the host element (e.g. '#theCtrl').
JavaScript object containing initialization data for the control.
Gets or sets the template used to instantiate Gauge controls.
Gets or sets the Range used to represent the gauge's overall geometry and appearance.
Gets or sets the format string used to display gauge values as text.
Gets or sets a callback that returns customized strings used to display gauge values.
Use this property if you want to customize the strings shown on the gauge in cases where the format property is not enough.
If provided, the callback should be a function as that takes as parameters the gauge, the part name, the value, and the formatted value. The callback should return the string to be displayed on the gauge.
For example:
// callback to convert values into strings
gauge.getText = function (gauge, part, value, text) {
switch (part) {
case 'value':
if (value <= 10) return 'Empty!';
if (value <= 25) return 'Low...';
if (value <= 95) return 'Good';
return 'Full';
case 'min':
return 'EMPTY';
case 'max':
return 'FULL';
}
return text;
}
Gets or sets a value that indicates whether the gauge displays a shadow effect.
Gets the DOM element that is hosting the control.
Gets or sets a value that indicates whether the gauge animates value changes.
Gets or sets a value that determines whether the control is disabled.
Disabled controls cannot get mouse or keyboard events.
Gets or sets a value that indicates whether the user can edit the value using the mouse and keyboard.
Gets a value that indicates whether the control is currently handling a touch event.
Gets a value that indicates whether the control is currently being updated.
Gets or sets the maximum value that can be displayed on the gauge.
For details about using the min and max properties, please see the Using the min and max properties topic.
Gets or sets the minimum value that can be displayed on the gauge.
For details about using the min and max properties, please see the Using the min and max properties topic.
Gets or sets the starting point used for painting the range.
By default, this property is set to null, which causes the value range to start at the gauge's minimum value, or zero if the minimum is less than zero.
Gets or sets the Range used to represent the gauge's current value.
Gets a value indicating whether the control is hosted in an element with right-to-left layout.
Gets or sets a value that indicates whether the gauge displays the ranges contained in the ranges property.
If this property is set to false, the ranges contained in the ranges property are not displayed in the gauge. Instead, they are used to interpolate the color of the pointer range while animating value changes.
Gets or sets the ShowText values to display as text in the gauge.
Gets or sets a property that determines whether the gauge should display tickmarks at each step value.
The tickmarks can be formatted in CSS using the wj-gauge and wj-ticks class names. For example:
.wj-gauge .wj-ticks {
stroke-width: 2px;
stroke: white;
}
Gets or sets the amount to add to or subtract from the value property when the user presses the arrow keys or moves the mouse wheel.
Gets or sets the thickness of the gauge, on a scale between zero and one.
Setting the thickness to one causes the gauge to fill as much of the control area as possible. Smaller values create thinner gauges.
Gets or sets the size of the element that shows the gauge's current value, in pixels.
addEventListener(target: EventTarget, type: string, fn: any, capture?: boolean): void
Adds an event listener to an element owned by this Control.
The control keeps a list of attached listeners and their handlers, making it easier to remove them when the control is disposed (see the dispose and removeEventListener method).
Failing to remove event listeners may cause memory leaks.
Target element for the event.
String that specifies the event.
Function to execute when the event occurs.
Whether the listener is capturing.
applyTemplate(classNames: string, template: string, parts: Object, namePart?: string): HTMLElement
Applies the template to a new instance of a control, and returns the root element.
This method should be called by constructors of templated controls. It is responsible for binding the template parts to the corresponding control members.
For example, the code below applies a template to an instance of an InputNumber control. The template must contain elements with the 'wj-part' attribute set to 'input', 'btn-inc', and 'btn-dec'. The control members '_tbx', '_btnUp', and '_btnDn' will be assigned references to these elements.
this.applyTemplate('wj-control wj-inputnumber', template, {
_tbx: 'input',
_btnUp: 'btn-inc',
_btnDn: 'btn-dec'
}, 'input');
Names of classes to add to the control's host element.
An HTML string that defines the control template.
A dictionary of part variables and their names.
Name of the part to be named after the host element. This determines how the control submits data when used in forms.
beginUpdate(): void
Suspends notifications until the next call to endUpdate.
deferUpdate(fn: Function): void
Executes a function within a beginUpdate/endUpdate block.
The control will not be updated until the function has been executed. This method ensures endUpdate is called even if the function throws an exception.
Function to be executed.
dispose(): void
Disposes of the control by removing its association with the host element.
The dispose method automatically removes any event listeners added with the addEventListener method.
Calling the dispose method is important in applications that create and remove controls dynamically. Failing to dispose of the controls may cause memory leaks.
disposeAll(e?: HTMLElement): void
Disposes of all Wijmo controls contained in an HTML element.
Container element.
endUpdate(): void
Resumes notifications suspended by calls to beginUpdate.
getControl(element: any): Control
Gets the control that is hosted in a given DOM element.
The DOM element that is hosting the control, or a selector for the host element (e.g. '#theCtrl').
getTemplate(): string
Gets the HTML template used to create instances of the control.
This method traverses up the class hierarchy to find the nearest ancestor that specifies a control template. For example, if you specify a prototype for the ComboBox control, it will override the template defined by the DropDown base class.
hitTest(pt: any, y?: number): number
Gets a number that corresponds to the value of the gauge at a given point.
For example:
// hit test a point when the user clicks on the gauge
gauge.hostElement.addEventListener('click', function (e) {
var ht = gauge.hitTest(e.pageX, e.pageY);
if (ht != null) {
console.log('you clicked the gauge at value ' + ht.toString());
}
});
The point to investigate, in window coordinates, or a MouseEvent object, or the x coordinate of the point.
The Y coordinate of the point (if the first parameter is a number).
initialize(options: any): void
Initializes the control by copying the properties from a given object.
This method allows you to initialize controls using plain data objects instead of setting the value of each property in code.
For example:
grid.initialize({
itemsSource: myList,
autoGenerateColumns: false,
columns: [
{ binding: 'id', header: 'Code', width: 130 },
{ binding: 'name', header: 'Name', width: 60 }
]
});
// is equivalent to
grid.itemsSource = myList;
grid.autoGenerateColumns = false;
// etc.
The initialization data is type-checked as it is applied. If the initialization object contains unknown property names or invalid data types, this method will throw.
Object that contains the initialization data.
invalidate(fullUpdate?: boolean): void
Invalidates the control causing an asynchronous refresh.
Whether to update the control layout as well as the content.
invalidateAll(e?: HTMLElement): void
Invalidates all Wijmo controls contained in an HTML element.
Use this method when your application has dynamic panels that change the control's visibility or dimensions. For example, splitters, accordions, and tab controls usually change the visibility of its content elements. In this case, failing to notify the controls contained in the element may cause them to stop working properly.
If this happens, you must handle the appropriate event in the dynamic container and call the invalidateAll method so the contained Wijmo controls will update their layout information properly.
Container element. If set to null, all Wijmo controls on the page will be invalidated.
onGotFocus(e?: EventArgs): void
Raises the gotFocus event.
onLostFocus(e?: EventArgs): void
Raises the lostFocus event.
onValueChanged(e?: EventArgs): void
Raises the valueChanged event.
refresh(fullUpdate?: boolean): void
Refreshes the control.
Indicates whether to update the control layout as well as the content.
refreshAll(e?: HTMLElement): void
Refreshes all Wijmo controls contained in an HTML element.
This method is similar to invalidateAll, except the controls are updated immediately rather than after an interval.
Container element. If set to null, all Wijmo controls on the page will be invalidated.
removeEventListener(target?: EventTarget, type?: string, fn?: any, capture?: boolean): number
Removes one or more event listeners attached to elements owned by this Control.
Target element for the event. If null, removes listeners attached to all targets.
String that specifies the event. If null, removes listeners attached to all events.
Handler to remove. If null, removes all handlers.
Whether the listener is capturing. If null, removes capturing and non-capturing listeners.
The LinearGauge displays a linear scale with an indicator that represents a single value and optional ranges to represent reference values.
If you set the gauge's isReadOnly property to false, then users will be able to edit the value by clicking on the gauge.
Example