ipsos-components
Version:
Material Design components for Angular
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text/typescript
/**
* @license
* Copyright Google LLC All Rights Reserved.
*
* Use of this source code is governed by an MIT-style license that can be
* found in the LICENSE file at https://angular.io/license
*/
import {FocusMonitor, FocusOrigin} from '@angular/cdk/a11y';
import {Directionality} from '@angular/cdk/bidi';
import {coerceBooleanProperty, coerceNumberProperty} from '@angular/cdk/coercion';
import {
DOWN_ARROW,
END,
HOME,
LEFT_ARROW,
PAGE_DOWN,
PAGE_UP,
RIGHT_ARROW,
UP_ARROW,
} from '@angular/cdk/keycodes';
import {
Attribute,
ChangeDetectionStrategy,
ChangeDetectorRef,
Component,
ElementRef,
EventEmitter,
forwardRef,
Input,
OnDestroy,
OnInit,
Optional,
Output,
ViewChild,
ViewEncapsulation,
} from '@angular/core';
import {ControlValueAccessor, NG_VALUE_ACCESSOR} from '@angular/forms';
import {
CanColor,
CanDisable,
HammerInput,
HasTabIndex,
mixinColor,
mixinDisabled,
mixinTabIndex,
} from '@angular/material/core';
import {Subscription} from 'rxjs/Subscription';
/**
* Visually, a 30px separation between tick marks looks best. This is very subjective but it is
* the default separation we chose.
*/
const MIN_AUTO_TICK_SEPARATION = 30;
/** The thumb gap size for a disabled slider. */
const DISABLED_THUMB_GAP = 7;
/** The thumb gap size for a non-active slider at its minimum value. */
const MIN_VALUE_NONACTIVE_THUMB_GAP = 7;
/** The thumb gap size for an active slider at its minimum value. */
const MIN_VALUE_ACTIVE_THUMB_GAP = 10;
/**
* Provider Expression that allows mat-slider to register as a ControlValueAccessor.
* This allows it to support [(ngModel)] and [formControl].
*/
export const MAT_SLIDER_VALUE_ACCESSOR: any = {
provide: NG_VALUE_ACCESSOR,
useExisting: forwardRef(() => MatSlider),
multi: true
};
/** A simple change event emitted by the MatSlider component. */
export class MatSliderChange {
/** The MatSlider that changed. */
source: MatSlider;
/** The new value of the source slider. */
value: number | null;
}
// Boilerplate for applying mixins to MatSlider.
/** @docs-private */
export class MatSliderBase {
constructor(public _elementRef: ElementRef) {}
}
export const _MatSliderMixinBase =
mixinTabIndex(mixinColor(mixinDisabled(MatSliderBase), 'accent'));
/**
* Allows users to select from a range of values by moving the slider thumb. It is similar in
* behavior to the native `<input type="range">` element.
*/
export class MatSlider extends _MatSliderMixinBase
implements ControlValueAccessor, OnDestroy, CanDisable, CanColor, OnInit, HasTabIndex {
/** Whether the slider is inverted. */
get invert() { return this._invert; }
set invert(value: any) {
this._invert = coerceBooleanProperty(value);
}
private _invert = false;
/** The maximum value that the slider can have. */
get max() { return this._max; }
set max(v: number) {
this._max = coerceNumberProperty(v, this._max);
this._percent = this._calculatePercentage(this._value);
// Since this also modifies the percentage, we need to let the change detection know.
this._changeDetectorRef.markForCheck();
}
private _max: number = 100;
/** The minimum value that the slider can have. */
get min() { return this._min; }
set min(v: number) {
this._min = coerceNumberProperty(v, this._min);
// If the value wasn't explicitly set by the user, set it to the min.
if (this._value === null) {
this.value = this._min;
}
this._percent = this._calculatePercentage(this._value);
// Since this also modifies the percentage, we need to let the change detection know.
this._changeDetectorRef.markForCheck();
}
private _min: number = 0;
/** The values at which the thumb will snap. */
get step() { return this._step; }
set step(v: number) {
this._step = coerceNumberProperty(v, this._step);
if (this._step % 1 !== 0) {
this._roundLabelTo = this._step.toString().split('.').pop()!.length;
}
// Since this could modify the label, we need to notify the change detection.
this._changeDetectorRef.markForCheck();
}
private _step: number = 1;
/** Whether or not to show the thumb label. */
get thumbLabel(): boolean { return this._thumbLabel; }
set thumbLabel(value) { this._thumbLabel = coerceBooleanProperty(value); }
private _thumbLabel: boolean = false;
/** @deprecated */
get _thumbLabelDeprecated(): boolean { return this._thumbLabel; }
set _thumbLabelDeprecated(value) { this._thumbLabel = value; }
/**
* How often to show ticks. Relative to the step so that a tick always appears on a step.
* Ex: Tick interval of 4 with a step of 3 will draw a tick every 4 steps (every 12 values).
*/
get tickInterval() { return this._tickInterval; }
set tickInterval(value: 'auto' | number) {
if (value === 'auto') {
this._tickInterval = 'auto';
} else if (typeof value === 'number' || typeof value === 'string') {
this._tickInterval = coerceNumberProperty(value, this._tickInterval as number);
} else {
this._tickInterval = 0;
}
}
private _tickInterval: 'auto' | number = 0;
/** @deprecated */
get _tickIntervalDeprecated() { return this.tickInterval; }
set _tickIntervalDeprecated(v) { this.tickInterval = v; }
/** Value of the slider. */
get value() {
// If the value needs to be read and it is still uninitialized, initialize it to the min.
if (this._value === null) {
this.value = this._min;
}
return this._value;
}
set value(v: number | null) {
if (v !== this._value) {
this._value = coerceNumberProperty(v, this._value || 0);
this._percent = this._calculatePercentage(this._value);
// Since this also modifies the percentage, we need to let the change detection know.
this._changeDetectorRef.markForCheck();
}
}
private _value: number | null = null;
/** Whether the slider is vertical. */
get vertical() { return this._vertical; }
set vertical(value: any) {
this._vertical = coerceBooleanProperty(value);
}
private _vertical = false;
/** Event emitted when the slider value has changed. */
change = new EventEmitter<MatSliderChange>();
/** Event emitted when the slider thumb moves. */
input = new EventEmitter<MatSliderChange>();
/** The value to be used for display purposes. */
get displayValue(): string | number {
// Note that this could be improved further by rounding something like 0.999 to 1 or
// 0.899 to 0.9, however it is very performance sensitive, because it gets called on
// every change detection cycle.
if (this._roundLabelTo && this.value && this.value % 1 !== 0) {
return this.value.toFixed(this._roundLabelTo);
}
return this.value || 0;
}
/** onTouch function registered via registerOnTouch (ControlValueAccessor). */
onTouched: () => any = () => {};
/** The percentage of the slider that coincides with the value. */
get percent(): number { return this._clamp(this._percent); }
private _percent: number = 0;
/**
* Whether or not the thumb is sliding.
* Used to determine if there should be a transition for the thumb and fill track.
*/
_isSliding: boolean = false;
/**
* Whether or not the slider is active (clicked or sliding).
* Used to shrink and grow the thumb as according to the Material Design spec.
*/
_isActive: boolean = false;
/**
* Whether the axis of the slider is inverted.
* (i.e. whether moving the thumb in the positive x or y direction decreases the slider's value).
*/
get _invertAxis() {
// Standard non-inverted mode for a vertical slider should be dragging the thumb from bottom to
// top. However from a y-axis standpoint this is inverted.
return this.vertical ? !this.invert : this.invert;
}
/** Whether the slider is at its minimum value. */
get _isMinValue() {
return this.percent === 0;
}
/**
* The amount of space to leave between the slider thumb and the track fill & track background
* elements.
*/
get _thumbGap() {
if (this.disabled) {
return DISABLED_THUMB_GAP;
}
if (this._isMinValue && !this.thumbLabel) {
return this._isActive ? MIN_VALUE_ACTIVE_THUMB_GAP : MIN_VALUE_NONACTIVE_THUMB_GAP;
}
return 0;
}
/** CSS styles for the track background element. */
get _trackBackgroundStyles(): { [key: string]: string } {
let axis = this.vertical ? 'Y' : 'X';
let sign = this._invertMouseCoords ? '-' : '';
return {
'transform': `translate${axis}(${sign}${this._thumbGap}px) scale${axis}(${1 - this.percent})`
};
}
/** CSS styles for the track fill element. */
get _trackFillStyles(): { [key: string]: string } {
let axis = this.vertical ? 'Y' : 'X';
let sign = this._invertMouseCoords ? '' : '-';
return {
'transform': `translate${axis}(${sign}${this._thumbGap}px) scale${axis}(${this.percent})`
};
}
/** CSS styles for the ticks container element. */
get _ticksContainerStyles(): { [key: string]: string } {
let axis = this.vertical ? 'Y' : 'X';
// For a horizontal slider in RTL languages we push the ticks container off the left edge
// instead of the right edge to avoid causing a horizontal scrollbar to appear.
let sign = !this.vertical && this._direction == 'rtl' ? '' : '-';
let offset = this._tickIntervalPercent / 2 * 100;
return {
'transform': `translate${axis}(${sign}${offset}%)`
};
}
/** CSS styles for the ticks element. */
get _ticksStyles(): { [key: string]: string } {
let tickSize = this._tickIntervalPercent * 100;
let backgroundSize = this.vertical ? `2px ${tickSize}%` : `${tickSize}% 2px`;
let axis = this.vertical ? 'Y' : 'X';
// Depending on the direction we pushed the ticks container, push the ticks the opposite
// direction to re-center them but clip off the end edge. In RTL languages we need to flip the
// ticks 180 degrees so we're really cutting off the end edge abd not the start.
let sign = !this.vertical && this._direction == 'rtl' ? '-' : '';
let rotate = !this.vertical && this._direction == 'rtl' ? ' rotate(180deg)' : '';
let styles: { [key: string]: string } = {
'backgroundSize': backgroundSize,
// Without translateZ ticks sometimes jitter as the slider moves on Chrome & Firefox.
'transform': `translateZ(0) translate${axis}(${sign}${tickSize / 2}%)${rotate}`
};
if (this._isMinValue && this._thumbGap) {
let side = this.vertical ?
(this._invertAxis ? 'Bottom' : 'Top') :
(this._invertAxis ? 'Right' : 'Left');
styles[`padding${side}`] = `${this._thumbGap}px`;
}
return styles;
}
get _thumbContainerStyles(): { [key: string]: string } {
let axis = this.vertical ? 'Y' : 'X';
// For a horizontal slider in RTL languages we push the thumb container off the left edge
// instead of the right edge to avoid causing a horizontal scrollbar to appear.
let invertOffset =
(this._direction == 'rtl' && !this.vertical) ? !this._invertAxis : this._invertAxis;
let offset = (invertOffset ? this.percent : 1 - this.percent) * 100;
return {
'transform': `translate${axis}(-${offset}%)`
};
}
/** The size of a tick interval as a percentage of the size of the track. */
private _tickIntervalPercent: number = 0;
/** The dimensions of the slider. */
private _sliderDimensions: ClientRect | null = null;
private _controlValueAccessorChangeFn: (value: any) => void = () => {};
/** Decimal places to round to, based on the step amount. */
private _roundLabelTo: number;
/** Subscription to the Directionality change EventEmitter. */
private _dirChangeSubscription = Subscription.EMPTY;
/** The value of the slider when the slide start event fires. */
private _valueOnSlideStart: number | null;
/** Reference to the inner slider wrapper element. */
private _sliderWrapper: ElementRef;
/**
* Whether mouse events should be converted to a slider position by calculating their distance
* from the right or bottom edge of the slider as opposed to the top or left.
*/
private get _invertMouseCoords() {
return (this._direction == 'rtl' && !this.vertical) ? !this._invertAxis : this._invertAxis;
}
/** The language direction for this slider element. */
private get _direction() {
return (this._dir && this._dir.value == 'rtl') ? 'rtl' : 'ltr';
}
constructor(elementRef: ElementRef,
private _focusMonitor: FocusMonitor,
private _changeDetectorRef: ChangeDetectorRef,
private _dir: Directionality,
tabIndex: string) {
super(elementRef);
this.tabIndex = parseInt(tabIndex) || 0;
}
ngOnInit() {
this._focusMonitor
.monitor(this._elementRef.nativeElement, true)
.subscribe((origin: FocusOrigin) => {
this._isActive = !!origin && origin !== 'keyboard';
this._changeDetectorRef.detectChanges();
});
if (this._dir) {
this._dirChangeSubscription = this._dir.change.subscribe(() => {
this._changeDetectorRef.markForCheck();
});
}
}
ngOnDestroy() {
this._focusMonitor.stopMonitoring(this._elementRef.nativeElement);
this._dirChangeSubscription.unsubscribe();
}
_onMouseenter() {
if (this.disabled) {
return;
}
// We save the dimensions of the slider here so we can use them to update the spacing of the
// ticks and determine where on the slider click and slide events happen.
this._sliderDimensions = this._getSliderDimensions();
this._updateTickIntervalPercent();
}
_onClick(event: MouseEvent) {
if (this.disabled) {
return;
}
let oldValue = this.value;
this._isSliding = false;
this._focusHostElement();
this._updateValueFromPosition({x: event.clientX, y: event.clientY});
/* Emit a change and input event if the value changed. */
if (oldValue != this.value) {
this._emitInputEvent();
this._emitChangeEvent();
}
}
_onSlide(event: HammerInput) {
if (this.disabled) {
return;
}
// The slide start event sometimes fails to fire on iOS, so if we're not already in the sliding
// state, call the slide start handler manually.
if (!this._isSliding) {
this._onSlideStart(null);
}
// Prevent the slide from selecting anything else.
event.preventDefault();
let oldValue = this.value;
this._updateValueFromPosition({x: event.center.x, y: event.center.y});
// Native range elements always emit `input` events when the value changed while sliding.
if (oldValue != this.value) {
this._emitInputEvent();
}
}
_onSlideStart(event: HammerInput | null) {
if (this.disabled || this._isSliding) {
return;
}
// Simulate mouseenter in case this is a mobile device.
this._onMouseenter();
this._isSliding = true;
this._focusHostElement();
this._valueOnSlideStart = this.value;
if (event) {
this._updateValueFromPosition({x: event.center.x, y: event.center.y});
event.preventDefault();
}
}
_onSlideEnd() {
this._isSliding = false;
if (this._valueOnSlideStart != this.value) {
this._emitChangeEvent();
}
this._valueOnSlideStart = null;
}
_onFocus() {
// We save the dimensions of the slider here so we can use them to update the spacing of the
// ticks and determine where on the slider click and slide events happen.
this._sliderDimensions = this._getSliderDimensions();
this._updateTickIntervalPercent();
}
_onBlur() {
this.onTouched();
}
_onKeydown(event: KeyboardEvent) {
if (this.disabled) { return; }
let oldValue = this.value;
switch (event.keyCode) {
case PAGE_UP:
this._increment(10);
break;
case PAGE_DOWN:
this._increment(-10);
break;
case END:
this.value = this.max;
break;
case HOME:
this.value = this.min;
break;
case LEFT_ARROW:
// NOTE: For a sighted user it would make more sense that when they press an arrow key on an
// inverted slider the thumb moves in that direction. However for a blind user, nothing
// about the slider indicates that it is inverted. They will expect left to be decrement,
// regardless of how it appears on the screen. For speakers ofRTL languages, they probably
// expect left to mean increment. Therefore we flip the meaning of the side arrow keys for
// RTL. For inverted sliders we prefer a good a11y experience to having it "look right" for
// sighted users, therefore we do not swap the meaning.
this._increment(this._direction == 'rtl' ? 1 : -1);
break;
case UP_ARROW:
this._increment(1);
break;
case RIGHT_ARROW:
// See comment on LEFT_ARROW about the conditions under which we flip the meaning.
this._increment(this._direction == 'rtl' ? -1 : 1);
break;
case DOWN_ARROW:
this._increment(-1);
break;
default:
// Return if the key is not one that we explicitly handle to avoid calling preventDefault on
// it.
return;
}
if (oldValue != this.value) {
this._emitInputEvent();
this._emitChangeEvent();
}
this._isSliding = true;
event.preventDefault();
}
_onKeyup() {
this._isSliding = false;
}
/** Increments the slider by the given number of steps (negative number decrements). */
private _increment(numSteps: number) {
this.value = this._clamp((this.value || 0) + this.step * numSteps, this.min, this.max);
}
/** Calculate the new value from the new physical location. The value will always be snapped. */
private _updateValueFromPosition(pos: {x: number, y: number}) {
if (!this._sliderDimensions) {
return;
}
let offset = this.vertical ? this._sliderDimensions.top : this._sliderDimensions.left;
let size = this.vertical ? this._sliderDimensions.height : this._sliderDimensions.width;
let posComponent = this.vertical ? pos.y : pos.x;
// The exact value is calculated from the event and used to find the closest snap value.
let percent = this._clamp((posComponent - offset) / size);
if (this._invertMouseCoords) {
percent = 1 - percent;
}
let exactValue = this._calculateValue(percent);
// This calculation finds the closest step by finding the closest whole number divisible by the
// step relative to the min.
let closestValue = Math.round((exactValue - this.min) / this.step) * this.step + this.min;
// The value needs to snap to the min and max.
this.value = this._clamp(closestValue, this.min, this.max);
}
/** Emits a change event if the current value is different from the last emitted value. */
private _emitChangeEvent() {
this._controlValueAccessorChangeFn(this.value);
this.change.emit(this._createChangeEvent());
}
/** Emits an input event when the current value is different from the last emitted value. */
private _emitInputEvent() {
this.input.emit(this._createChangeEvent());
}
/** Updates the amount of space between ticks as a percentage of the width of the slider. */
private _updateTickIntervalPercent() {
if (!this.tickInterval || !this._sliderDimensions) {
return;
}
if (this.tickInterval == 'auto') {
let trackSize = this.vertical ? this._sliderDimensions.height : this._sliderDimensions.width;
let pixelsPerStep = trackSize * this.step / (this.max - this.min);
let stepsPerTick = Math.ceil(MIN_AUTO_TICK_SEPARATION / pixelsPerStep);
let pixelsPerTick = stepsPerTick * this.step;
this._tickIntervalPercent = pixelsPerTick / trackSize;
} else {
this._tickIntervalPercent = this.tickInterval * this.step / (this.max - this.min);
}
}
/** Creates a slider change object from the specified value. */
private _createChangeEvent(value = this.value): MatSliderChange {
let event = new MatSliderChange();
event.source = this;
event.value = value;
return event;
}
/** Calculates the percentage of the slider that a value is. */
private _calculatePercentage(value: number | null) {
return ((value || 0) - this.min) / (this.max - this.min);
}
/** Calculates the value a percentage of the slider corresponds to. */
private _calculateValue(percentage: number) {
return this.min + percentage * (this.max - this.min);
}
/** Return a number between two numbers. */
private _clamp(value: number, min = 0, max = 1) {
return Math.max(min, Math.min(value, max));
}
/**
* Get the bounding client rect of the slider track element.
* The track is used rather than the native element to ignore the extra space that the thumb can
* take up.
*/
private _getSliderDimensions() {
return this._sliderWrapper ? this._sliderWrapper.nativeElement.getBoundingClientRect() : null;
}
/**
* Focuses the native element.
* Currently only used to allow a blur event to fire but will be used with keyboard input later.
*/
private _focusHostElement() {
this._elementRef.nativeElement.focus();
}
/**
* Sets the model value. Implemented as part of ControlValueAccessor.
* @param value
*/
writeValue(value: any) {
this.value = value;
}
/**
* Registers a callback to eb triggered when the value has changed.
* Implemented as part of ControlValueAccessor.
* @param fn Callback to be registered.
*/
registerOnChange(fn: (value: any) => void) {
this._controlValueAccessorChangeFn = fn;
}
/**
* Registers a callback to be triggered when the component is touched.
* Implemented as part of ControlValueAccessor.
* @param fn Callback to be registered.
*/
registerOnTouched(fn: any) {
this.onTouched = fn;
}
/**
* Sets whether the component should be disabled.
* Implemented as part of ControlValueAccessor.
* @param isDisabled
*/
setDisabledState(isDisabled: boolean) {
this.disabled = isDisabled;
}
}