The {@link LabelFormatter} interface defines a formatter to be used to render text within the * value indicator label on interaction. * *
{@link BasicLabelFormatter} is a simple implementation of the {@link LabelFormatter} that * displays the selected value using letters to indicate magnitude (e.g.: 1.5K, 3M, 12B, etc..). * *
With the default style {@link * com.google.android.material.R.style#Widget_MaterialComponents_Slider}, colorPrimary and * colorOnPrimary are used to customize the color of the slider when enabled, and colorOnSurface is * used when disabled. The following attributes are used to customize the slider's appearance * further: * *
The following XML attributes are used to set the slider's various parameters of operation: * *
The {@code valueFrom} value must be strictly lower than the {@code valueTo} value. If that * is not the case, an {@link IllegalStateException} will be thrown when the view is laid out. * * @param valueFrom The minimum value for the slider's range of values * @see #getValueFrom() * @attr ref com.google.android.material.R.styleable#Slider_android_valueFrom */ public void setValueFrom(float valueFrom) { this.valueFrom = valueFrom; dirtyConfig = true; postInvalidate(); } /** * Returns the slider's {@code valueTo} value. * * @see #setValueTo(float) * @attr ref com.google.android.material.R.styleable#Slider_android_valueTo */ public float getValueTo() { return valueTo; } /** * Sets the slider's {@code valueTo} value. * *
The {@code valueTo} value must be strictly greater than the {@code valueFrom} value. If that
* is not the case, an {@link IllegalStateException} will be thrown when the view is laid out.
*
* @param valueTo The maximum value for the slider's range of values
* @see #getValueTo()
* @attr ref com.google.android.material.R.styleable#Slider_android_valueTo
*/
public void setValueTo(float valueTo) {
this.valueTo = valueTo;
dirtyConfig = true;
postInvalidate();
}
@NonNull
List Each value must be greater or equal to {@code valueFrom}, and lesser or equal to {@code
* valueTo}. If that is not the case, an {@link IllegalStateException} will be thrown when the
* view is laid out.
*
* If the slider is in discrete mode (i.e. the tick increment value is greater than 0), the
* values must be set to a value falls on a tick (i.e.: {@code value == valueFrom + x * stepSize},
* where {@code x} is an integer equal to or greater than 0). If that is not the case, an {@link
* IllegalStateException} will be thrown when the view is laid out.
*
* @param values An array of values to set.
* @see #getValues()
*/
void setValues(@NonNull Float... values) {
ArrayList Each value must be greater or equal to {@code valueFrom}, and lesser or equal to {@code
* valueTo}. If that is not the case, an {@link IllegalStateException} will be thrown when the
* view is laid out.
*
* If the slider is in discrete mode (i.e. the tick increment value is greater than 0), the
* values must be set to a value falls on a tick (i.e.: {@code value == valueFrom + x * stepSize},
* where {@code x} is an integer equal to or greater than 0). If that is not the case, an {@link
* IllegalStateException} will be thrown when the view is laid out.
*
* @param values An array of values to set.
* @throws IllegalArgumentException If {@code values} is empty.
*/
void setValues(@NonNull List A step size of 0 means that the slider is operating in continuous mode. A step size greater
* than 0 means that the slider is operating in discrete mode.
*
* @see #setStepSize(float)
* @attr ref com.google.android.material.R.styleable#Slider_android_stepSize
*/
public float getStepSize() {
return stepSize;
}
/**
* Sets the step size to use to mark the ticks.
*
* Setting this value to 0 will make the slider operate in continuous mode. Setting this value
* to a number greater than 0 will make the slider operate in discrete mode.
*
* The step size must evenly divide the range described by the {@code valueFrom} and {@code
* valueTo}, it must be a factor of the range. If the step size is not a factor of the range, an
* {@link IllegalStateException} will be thrown when this view is laid out.
*
* Setting this value to a negative value will result in an {@link IllegalArgumentException}.
*
* @param stepSize The interval value at which ticks must be drawn. Set to 0 to operate the slider
* in continuous mode and not have any ticks.
* @throws IllegalArgumentException If the step size is less than 0
* @see #getStepSize()
* @attr ref com.google.android.material.R.styleable#Slider_android_stepSize
*/
public void setStepSize(float stepSize) {
if (stepSize < 0.0f) {
throw new IllegalArgumentException(
String.format(
EXCEPTION_ILLEGAL_STEP_SIZE,
Float.toString(stepSize),
Float.toString(valueFrom),
Float.toString(valueTo)));
}
if (this.stepSize != stepSize) {
this.stepSize = stepSize;
dirtyConfig = true;
postInvalidate();
}
}
/** Returns the index of the currently focused thumb */
public int getFocusedThumbIndex() {
return focusedThumbIdx;
}
/** Sets the index of the currently focused thumb */
public void setFocusedThumbIndex(int index) {
if (index < 0 || index >= values.size()) {
throw new IllegalArgumentException("index out of range");
}
focusedThumbIdx = index;
accessibilityHelper.requestKeyboardFocusForVirtualView(focusedThumbIdx);
postInvalidate();
}
/** Returns the index of the currently active thumb, or -1 if no thumb is active */
public int getActiveThumbIndex() {
return activeThumbIdx;
}
/**
* Registers a callback to be invoked when the slider changes.
*
* @param listener The callback to run when the slider changes
*/
public void addOnChangeListener(@Nullable L listener) {
changeListeners.add(listener);
}
/**
* Removes a callback for value changes from this slider.
*
* @param listener The callback that'll stop receive slider changes
*/
public void removeOnChangeListener(@NonNull L listener) {
changeListeners.remove(listener);
}
/** Removes all instances of attached to this slider */
public void clearOnChangeListeners() {
changeListeners.clear();
}
/**
* Registers a callback to be invoked when the slider touch event is being started or stopped
*
* @param listener The callback to run when the slider starts or stops being touched
*/
public void addOnSliderTouchListener(@NonNull T listener) {
touchListeners.add(listener);
}
/**
* Removes a callback to be invoked when the slider touch event is being started or stopped
*
* @param listener The callback that'll stop be notified when the slider is being touched
*/
public void removeOnSliderTouchListener(@NonNull T listener) {
touchListeners.remove(listener);
}
/** Removes all instances of touch listeners attached to this slider */
public void clearOnSliderTouchListeners() {
touchListeners.clear();
}
/**
* Returns {@code true} if the slider has a {@link LabelFormatter} attached, {@code false}
* otherwise.
*/
public boolean hasLabelFormatter() {
return formatter != null;
}
/**
* Registers a {@link LabelFormatter} to be used to format the value displayed in the bubble shown
* when the slider operates in discrete mode.
*
* @param formatter The {@link LabelFormatter} to use to format the bubble's text
*/
public void setLabelFormatter(@Nullable LabelFormatter formatter) {
this.formatter = formatter;
}
/**
* Returns the elevation of the thumb.
*
* @see #setThumbElevation(float)
* @see #setThumbElevationResource(int)
* @attr ref com.google.android.material.R.styleable#Slider_thumbElevation
*/
public float getThumbElevation() {
return thumbDrawable.getElevation();
}
/**
* Sets the elevation of the thumb.
*
* @see #getThumbElevation()
* @attr ref com.google.android.material.R.styleable#Slider_thumbElevation
*/
public void setThumbElevation(float elevation) {
thumbDrawable.setElevation(elevation);
}
/**
* Sets the elevation of the thumb from a dimension resource.
*
* @see #getThumbElevation()
* @attr ref com.google.android.material.R.styleable#Slider_thumbElevation
*/
public void setThumbElevationResource(@DimenRes int elevation) {
setThumbElevation(getResources().getDimension(elevation));
}
/**
* Returns the radius of the thumb.
*
* @see #setThumbRadius(int)
* @see #setThumbRadiusResource(int)
* @attr ref com.google.android.material.R.styleable#Slider_thumbRadius
*/
@Dimension
public int getThumbRadius() {
return thumbRadius;
}
/**
* Sets the radius of the thumb in pixels.
*
* @see #getThumbRadius()
* @attr ref com.google.android.material.R.styleable#Slider_thumbRadius
*/
public void setThumbRadius(@IntRange(from = 0) @Dimension int radius) {
if (radius == thumbRadius) {
return;
}
thumbRadius = radius;
thumbDrawable.setShapeAppearanceModel(
ShapeAppearanceModel.builder().setAllCorners(CornerFamily.ROUNDED, thumbRadius).build());
thumbDrawable.setBounds(0, 0, thumbRadius * 2, thumbRadius * 2);
postInvalidate();
}
/**
* Sets the radius of the thumb from a dimension resource.
*
* @see #getThumbRadius()
* @attr ref com.google.android.material.R.styleable#Slider_thumbRadius
*/
public void setThumbRadiusResource(@DimenRes int radius) {
setThumbRadius(getResources().getDimensionPixelSize(radius));
}
/**
* Returns the radius of the halo.
*
* @see #setHaloRadius(int)
* @see #setHaloRadiusResource(int)
* @attr ref com.google.android.material.R.styleable#Slider_haloRadius
*/
@Dimension()
public int getHaloRadius() {
return haloRadius;
}
/**
* Sets the radius of the halo in pixels.
*
* @see #getHaloRadius()
* @attr ref com.google.android.material.R.styleable#Slider_haloRadius
*/
public void setHaloRadius(@IntRange(from = 0) @Dimension int radius) {
if (radius == haloRadius) {
return;
}
haloRadius = radius;
if (!shouldDrawCompatHalo()) {
Drawable background = getBackground();
if (background instanceof RippleDrawable) {
DrawableUtils.setRippleDrawableRadius((RippleDrawable) background, haloRadius);
}
} else {
postInvalidate();
}
}
/**
* Sets the radius of the halo from a dimension resource.
*
* @see #getHaloRadius()
* @attr ref com.google.android.material.R.styleable#Slider_haloRadius
*/
public void setHaloRadiusResource(@DimenRes int radius) {
setHaloRadius(getResources().getDimensionPixelSize(radius));
}
/**
* Returns the {@link LabelBehavior} used.
*
* @see #setLabelBehavior(int)
* @attr ref com.google.android.material.R.styleable#Slider_labelBehavior
*/
@LabelBehavior
public int getLabelBehavior() {
return labelBehavior;
}
/**
* Determines the {@link LabelBehavior} used.
*
* @see LabelBehavior
* @see #getLabelBehavior()
* @attr ref com.google.android.material.R.styleable#Slider_labelBehavior
*/
public void setLabelBehavior(@LabelBehavior int labelBehavior) {
if (this.labelBehavior != labelBehavior) {
this.labelBehavior = labelBehavior;
requestLayout();
}
}
/** Returns the side padding of the track. */
@Dimension()
public int getTrackSidePadding() {
return trackSidePadding;
}
/** Returns the width of the track in pixels. */
@Dimension()
public int getTrackWidth() {
return trackWidth;
}
/**
* Returns the height of the track in pixels.
*
* @see #setTrackHeight(int)
* @attr ref com.google.android.material.R.styleable#Slider_trackHeight
*/
@Dimension()
public int getTrackHeight() {
return trackHeight;
}
/**
* Set the height of the track in pixels.
*
* @see #getTrackHeight()
* @attr ref com.google.android.material.R.styleable#Slider_trackHeight
*/
public void setTrackHeight(@IntRange(from = 0) @Dimension int trackHeight) {
if (this.trackHeight != trackHeight) {
this.trackHeight = trackHeight;
invalidateTrack();
postInvalidate();
}
}
/**
* Returns the color of the halo.
*
* @see #setHaloTintList(ColorStateList)
* @attr ref com.google.android.material.R.styleable#Slider_haloColor
*/
@NonNull
public ColorStateList getHaloTintList() {
return haloColor;
}
/**
* Sets the color of the halo.
*
* @see #getHaloTintList()
* @attr ref com.google.android.material.R.styleable#Slider_haloColor
*/
public void setHaloTintList(@NonNull ColorStateList haloColor) {
if (haloColor.equals(this.haloColor)) {
return;
}
this.haloColor = haloColor;
if (!shouldDrawCompatHalo()) {
Drawable background = getBackground();
if (background instanceof RippleDrawable) {
((RippleDrawable) background).setColor(haloColor);
}
} else {
haloPaint.setColor(getColorForState(haloColor));
haloPaint.setAlpha(HALO_ALPHA);
invalidate();
}
}
/**
* Returns the color of the thumb.
*
* @see #setThumbTintList(ColorStateList)
* @attr ref com.google.android.material.R.styleable#Slider_thumbColor
*/
@NonNull
public ColorStateList getThumbTintList() {
return thumbDrawable.getFillColor();
}
/**
* Sets the color of the thumb.
*
* @see #getThumbTintList()
* @attr ref com.google.android.material.R.styleable#Slider_thumbColor
*/
public void setThumbTintList(@NonNull ColorStateList thumbColor) {
thumbDrawable.setFillColor(thumbColor);
}
/**
* Returns the color of the tick if the active and inactive parts aren't different.
*
* @throws IllegalStateException If {@code tickColorActive} and {@code tickColorInactive} have
* been set to different values.
* @see #setTickTintList(ColorStateList)
* @see #setTickInactiveTintList(ColorStateList)
* @see #setTickActiveTintList(ColorStateList)
* @see #getTickInactiveTintList()
* @see #getTickActiveTintList()
* @attr ref com.google.android.material.R.styleable#Slider_tickColor
*/
@NonNull
public ColorStateList getTickTintList() {
if (!tickColorInactive.equals(tickColorActive)) {
throw new IllegalStateException(
"The inactive and active ticks are different colors. Use the getTickColorInactive() and"
+ " getTickColorActive() methods instead.");
}
return tickColorActive;
}
/**
* Sets the color of the tick marks.
*
* @see #setTickInactiveTintList(ColorStateList)
* @see #setTickActiveTintList(ColorStateList)
* @see #getTickTintList()
* @attr ref com.google.android.material.R.styleable#Slider_tickColor
*/
public void setTickTintList(@NonNull ColorStateList tickColor) {
setTickInactiveTintList(tickColor);
setTickActiveTintList(tickColor);
}
/**
* Returns the color of the ticks on the active portion of the track.
*
* @see #setTickActiveTintList(ColorStateList)
* @see #setTickTintList(ColorStateList)
* @see #getTickTintList()
* @attr ref com.google.android.material.R.styleable#Slider_tickColorActive
*/
@NonNull
public ColorStateList getTickActiveTintList() {
return tickColorActive;
}
/**
* Sets the color of the ticks on the active portion of the track.
*
* @see #getTickActiveTintList()
* @see #setTickTintList(ColorStateList)
* @attr ref com.google.android.material.R.styleable#Slider_tickColorActive
*/
public void setTickActiveTintList(@NonNull ColorStateList tickColor) {
if (tickColor.equals(tickColorActive)) {
return;
}
tickColorActive = tickColor;
activeTicksPaint.setColor(getColorForState(tickColorActive));
invalidate();
}
/**
* Returns the color of the ticks on the inactive portion of the track.
*
* @see #setTickInactiveTintList(ColorStateList)
* @see #setTickTintList(ColorStateList)
* @see #getTickTintList()
* @attr ref com.google.android.material.R.styleable#Slider_tickColorInactive
*/
@NonNull
public ColorStateList getTickInactiveTintList() {
return tickColorInactive;
}
/**
* Sets the color of the ticks on the inactive portion of the track.
*
* @see #getTickInactiveTintList()
* @see #setTickTintList(ColorStateList)
* @attr ref com.google.android.material.R.styleable#Slider_tickColorInactive
*/
public void setTickInactiveTintList(@NonNull ColorStateList tickColor) {
if (tickColor.equals(tickColorInactive)) {
return;
}
tickColorInactive = tickColor;
inactiveTicksPaint.setColor(getColorForState(tickColorInactive));
invalidate();
}
/**
* Returns the color of the track if the active and inactive parts aren't different.
*
* @throws IllegalStateException If {@code trackColorActive} and {@code trackColorInactive} have
* been set to different values.
* @see #setTrackTintList(ColorStateList)
* @see #setTrackInactiveTintList(ColorStateList)
* @see #setTrackActiveTintList(ColorStateList)
* @see #getTrackInactiveTintList()
* @see #getTrackActiveTintList()
* @attr ref com.google.android.material.R.styleable#Slider_trackColor
*/
@NonNull
public ColorStateList getTrackTintList() {
if (!trackColorInactive.equals(trackColorActive)) {
throw new IllegalStateException(
"The inactive and active parts of the track are different colors. Use the"
+ " getInactiveTrackColor() and getActiveTrackColor() methods instead.");
}
return trackColorActive;
}
/**
* Sets the color of the track.
*
* @see #setTrackInactiveTintList(ColorStateList)
* @see #setTrackActiveTintList(ColorStateList)
* @see #getTrackTintList()
* @attr ref com.google.android.material.R.styleable#Slider_trackColor
*/
public void setTrackTintList(@NonNull ColorStateList trackColor) {
setTrackInactiveTintList(trackColor);
setTrackActiveTintList(trackColor);
}
/**
* Returns the color of the active portion of the track.
*
* @see #setTrackActiveTintList(ColorStateList)
* @see #setTrackTintList(ColorStateList)
* @see #getTrackTintList()
* @attr ref com.google.android.material.R.styleable#Slider_trackColorActive
*/
@NonNull
public ColorStateList getTrackActiveTintList() {
return trackColorActive;
}
/**
* Sets the color of the active portion of the track.
*
* @see #getTrackActiveTintList()
* @see #setTrackTintList(ColorStateList)
* @attr ref com.google.android.material.R.styleable#Slider_trackColorActive
*/
public void setTrackActiveTintList(@NonNull ColorStateList trackColor) {
if (trackColor.equals(trackColorActive)) {
return;
}
trackColorActive = trackColor;
activeTrackPaint.setColor(getColorForState(trackColorActive));
invalidate();
}
/**
* Returns the color of the inactive portion of the track.
*
* @see #setTrackInactiveTintList(ColorStateList)
* @see #setTrackTintList(ColorStateList)
* @see #getTrackTintList()
* @attr ref com.google.android.material.R.styleable#Slider_trackColorInactive
*/
@NonNull
public ColorStateList getTrackInactiveTintList() {
return trackColorInactive;
}
/**
* Sets the color of the inactive portion of the track.
*
* @see #getTrackInactiveTintList()
* @see #setTrackTintList(ColorStateList)
* @attr ref com.google.android.material.R.styleable#Slider_trackColorInactive
*/
public void setTrackInactiveTintList(@NonNull ColorStateList trackColor) {
if (trackColor.equals(trackColorInactive)) {
return;
}
trackColorInactive = trackColor;
inactiveTrackPaint.setColor(getColorForState(trackColorInactive));
invalidate();
}
@Override
public void setEnabled(boolean enabled) {
super.setEnabled(enabled);
// When we're disabled, set the layer type to hardware so we can clear the track out from behind
// the thumb.
setLayerType(enabled ? LAYER_TYPE_NONE : LAYER_TYPE_HARDWARE, null);
}
@Override
protected void onAttachedToWindow() {
super.onAttachedToWindow();
// The label is attached on the Overlay relative to the content.
for (TooltipDrawable label : labels) {
label.setRelativeToView(ViewUtils.getContentView(this));
}
}
@Override
protected void onDetachedFromWindow() {
if (accessibilityEventSender != null) {
removeCallbacks(accessibilityEventSender);
}
for (TooltipDrawable label : labels) {
ViewOverlayImpl contentViewOverlay = ViewUtils.getContentViewOverlay(this);
if (contentViewOverlay != null) {
contentViewOverlay.remove(label);
label.detachView(ViewUtils.getContentView(this));
}
}
super.onDetachedFromWindow();
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(
widthMeasureSpec,
MeasureSpec.makeMeasureSpec(
widgetHeight
+ (labelBehavior == LABEL_WITHIN_BOUNDS ? labels.get(0).getIntrinsicHeight() : 0),
MeasureSpec.EXACTLY));
}
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
// Update the visible track width.
trackWidth = w - trackSidePadding * 2;
// Update the visible tick coordinates.
if (stepSize > 0.0f) {
calculateTicksCoordinates();
}
updateHaloHotspot();
}
private void calculateTicksCoordinates() {
validateConfigurationIfDirty();
int tickCount = (int) ((valueTo - valueFrom) / stepSize + 1);
// Limit the tickCount if they will be too dense.
tickCount = Math.min(tickCount, trackWidth / (trackHeight * 2) + 1);
if (ticksCoordinates == null || ticksCoordinates.length != tickCount * 2) {
ticksCoordinates = new float[tickCount * 2];
}
float interval = trackWidth / (float) (tickCount - 1);
for (int i = 0; i < tickCount * 2; i += 2) {
ticksCoordinates[i] = trackSidePadding + i / 2 * interval;
ticksCoordinates[i + 1] = calculateTop();
}
}
private void updateHaloHotspot() {
// Set the hotspot as the halo if RippleDrawable is being used.
if (!shouldDrawCompatHalo() && getMeasuredWidth() > 0) {
final Drawable background = getBackground();
if (background instanceof RippleDrawable) {
int x = (int) (normalizeValue(values.get(focusedThumbIdx)) * trackWidth + trackSidePadding);
int y = calculateTop();
DrawableCompat.setHotspotBounds(
background, x - haloRadius, y - haloRadius, x + haloRadius, y + haloRadius);
}
}
}
private int calculateTop() {
return trackTop
+ (labelBehavior == LABEL_WITHIN_BOUNDS ? labels.get(0).getIntrinsicHeight() : 0);
}
@Override
protected void onDraw(@NonNull Canvas canvas) {
if (dirtyConfig) {
validateConfigurationIfDirty();
// Update the visible tick coordinates.
if (stepSize > 0.0f) {
calculateTicksCoordinates();
}
}
super.onDraw(canvas);
int top = calculateTop();
drawInactiveTrack(canvas, trackWidth, top);
if (Collections.max(getValues()) > valueFrom) {
drawActiveTrack(canvas, trackWidth, top);
}
if (stepSize > 0.0f) {
drawTicks(canvas);
}
if ((thumbIsPressed || isFocused()) && isEnabled()) {
maybeDrawHalo(canvas, trackWidth, top);
// Draw labels if there is an active thumb.
if (activeThumbIdx != -1) {
ensureLabels();
}
}
drawThumbs(canvas, trackWidth, top);
}
/**
* Returns a float array where {@code float[0]} is the normalized left position and {@code
* float[1]} is the normalized right position of the range.
*/
private float[] getActiveRange() {
float max = Collections.max(getValues());
float min = Collections.min(getValues());
float left = normalizeValue(values.size() == 1 ? valueFrom : min);
float right = normalizeValue(max);
// In RTL we draw things in reverse, so swap the left and right range values
if (ViewCompat.getLayoutDirection(this) == ViewCompat.LAYOUT_DIRECTION_RTL) {
return new float[] {right, left};
} else {
return new float[] {left, right};
}
}
private void drawInactiveTrack(@NonNull Canvas canvas, int width, int top) {
float[] activeRange = getActiveRange();
float right = trackSidePadding + activeRange[1] * width;
if (right < trackSidePadding + width) {
canvas.drawLine(right, top, trackSidePadding + width, top, inactiveTrackPaint);
}
// Also draw inactive track to the left if there is any
float left = trackSidePadding + activeRange[0] * width;
if (left > trackSidePadding) {
canvas.drawLine(trackSidePadding, top, left, top, inactiveTrackPaint);
}
}
/**
* Returns a number between 0 and 1 indicating where on the track this value should sit with 0
* being on the far left, and 1 on the far right.
*/
private float normalizeValue(float value) {
float normalized = (value - valueFrom) / (valueTo - valueFrom);
if (ViewCompat.getLayoutDirection(this) == ViewCompat.LAYOUT_DIRECTION_RTL) {
return 1 - normalized;
}
return normalized;
}
private void drawActiveTrack(@NonNull Canvas canvas, int width, int top) {
float[] activeRange = getActiveRange();
float right = trackSidePadding + activeRange[1] * width;
float left = trackSidePadding + activeRange[0] * width;
canvas.drawLine(left, top, right, top, activeTrackPaint);
}
private void drawTicks(@NonNull Canvas canvas) {
float[] activeRange = getActiveRange();
int leftPivotIndex = pivotIndex(ticksCoordinates, activeRange[0]);
int rightPivotIndex = pivotIndex(ticksCoordinates, activeRange[1]);
// Draw inactive ticks to the left of the smallest thumb.
canvas.drawPoints(ticksCoordinates, 0, leftPivotIndex * 2, inactiveTicksPaint);
// Draw active ticks between the thumbs.
canvas.drawPoints(
ticksCoordinates,
leftPivotIndex * 2,
rightPivotIndex * 2 - leftPivotIndex * 2,
activeTicksPaint);
// Draw inactive ticks to the right of the largest thumb.
canvas.drawPoints(
ticksCoordinates,
rightPivotIndex * 2,
ticksCoordinates.length - rightPivotIndex * 2,
inactiveTicksPaint);
}
private void drawThumbs(@NonNull Canvas canvas, int width, int top) {
// Clear out the track behind the thumb if we're in a disable state since the thumb is
// transparent.
if (!isEnabled()) {
for (Float value : values) {
canvas.drawCircle(
trackSidePadding + normalizeValue(value) * width, top, thumbRadius, thumbPaint);
}
}
for (Float value : values) {
canvas.save();
canvas.translate(
trackSidePadding + (int) (normalizeValue(value) * width) - thumbRadius,
top - thumbRadius);
thumbDrawable.draw(canvas);
canvas.restore();
}
}
private void maybeDrawHalo(@NonNull Canvas canvas, int width, int top) {
// Only draw the halo for devices that aren't using the ripple.
if (shouldDrawCompatHalo()) {
int centerX = (int) (trackSidePadding + normalizeValue(values.get(focusedThumbIdx)) * width);
if (VERSION.SDK_INT < VERSION_CODES.P) {
// In this case we can clip the rect to allow drawing outside the bounds.
canvas.clipRect(
centerX - haloRadius,
top - haloRadius,
centerX + haloRadius,
top + haloRadius,
Op.UNION);
}
canvas.drawCircle(centerX, top, haloRadius, haloPaint);
}
}
private boolean shouldDrawCompatHalo() {
return forceDrawCompatHalo
|| VERSION.SDK_INT < VERSION_CODES.LOLLIPOP
|| !(getBackground() instanceof RippleDrawable);
}
@Override
public boolean onTouchEvent(@NonNull MotionEvent event) {
if (!isEnabled()) {
return false;
}
float x = event.getX();
touchPosition = (x - trackSidePadding) / trackWidth;
touchPosition = Math.max(0, touchPosition);
touchPosition = Math.min(1, touchPosition);
switch (event.getActionMasked()) {
case MotionEvent.ACTION_DOWN:
touchDownX = x;
// If we're inside a scrolling container,
// we should start dragging in ACTION_MOVE
if (isInScrollingContainer()) {
break;
}
getParent().requestDisallowInterceptTouchEvent(true);
if (!pickActiveThumb()) {
// Couldn't determine the active thumb yet.
break;
}
requestFocus();
thumbIsPressed = true;
snapTouchPosition();
updateHaloHotspot();
invalidate();
onStartTrackingTouch();
break;
case MotionEvent.ACTION_MOVE:
if (!thumbIsPressed) {
// Check if we're trying to scroll instead of dragging this Slider
if (Math.abs(x - touchDownX) < scaledTouchSlop) {
return false;
}
getParent().requestDisallowInterceptTouchEvent(true);
onStartTrackingTouch();
}
if (!pickActiveThumb()) {
// Couldn't determine the active thumb yet.
break;
}
thumbIsPressed = true;
snapTouchPosition();
updateHaloHotspot();
invalidate();
break;
case MotionEvent.ACTION_UP:
thumbIsPressed = false;
// We need to handle a tap if the last event was down at the same point.
if (lastEvent != null
&& lastEvent.getActionMasked() == MotionEvent.ACTION_DOWN
&& lastEvent.getX() == event.getX()
&& lastEvent.getY() == event.getY()) {
pickActiveThumb();
}
if (activeThumbIdx != -1) {
snapTouchPosition();
activeThumbIdx = -1;
}
for (TooltipDrawable label : labels) {
ViewUtils.getContentViewOverlay(this).remove(label);
}
onStopTrackingTouch();
invalidate();
break;
default:
// Nothing to do in this case.
}
// Set if the thumb is pressed. This will cause the ripple to be drawn.
setPressed(thumbIsPressed);
lastEvent = MotionEvent.obtain(event);
return true;
}
/**
* Calculates the index the closest tick coordinates that the thumb should snap to.
*
* @param coordinates Tick coordinates defined in {@code #setTicksCoordinates()}.
* @param position Actual thumb position.
* @return Index of the closest tick coordinate.
*/
private static int pivotIndex(float[] coordinates, float position) {
return Math.round(position * (coordinates.length / 2 - 1));
}
private double snapPosition(float position) {
if (stepSize > 0.0f) {
int stepCount = (int) ((valueTo - valueFrom) / stepSize);
return Math.round(position * stepCount) / (double) stepCount;
}
return position;
}
/**
* Tries to pick the active thumb if one hasn't already been set. This will pick the closest thumb
* if there is only one thumb under the touch position. If there is more than one thumb under the
* touch position, it will wait for enough drag left or right to determine which thumb to pick.
*/
private boolean pickActiveThumb() {
if (activeThumbIdx != -1) {
return true;
}
float touchValue = getValueOfTouchPosition();
float touchX = valueToX(touchValue);
float leftXBound = Math.min(touchX, touchDownX);
float rightXBound = Math.max(touchX, touchDownX);
activeThumbIdx = 0;
float activeThumbDiff = Math.abs(values.get(activeThumbIdx) - touchValue);
for (int i = 0; i < values.size(); i++) {
float valueDiff = Math.abs(values.get(i) - touchValue);
float valueX = valueToX(values.get(i));
float valueDiffX = Math.abs(valueX - touchX);
float activeValueDiffX = Math.abs(valueToX(values.get(activeThumbIdx)) - touchX);
// Check if we've received touch events that's passing over a thumb.
if (leftXBound < valueX && rightXBound > valueX) {
activeThumbIdx = i;
return true;
}
// If the new point and the active point are both within scaled touch slop of the touch and
// the value is not the same, we have to wait for the touch to move.
if (valueDiffX < scaledTouchSlop
&& activeValueDiffX < scaledTouchSlop
&& Math.abs(valueDiffX - activeValueDiffX) > THRESHOLD) {
activeThumbIdx = -1;
return false;
}
if (valueDiff < activeThumbDiff) {
// This value is closer to the thumb so update the active thumb index.
activeThumbDiff = valueDiff;
activeThumbIdx = i;
}
}
return true;
}
/**
* Snaps the thumb position to the closest tick coordinates in discrete mode, and the input
* position in continuous mode.
*
* @return true, if {@code #thumbPosition is updated}; false, otherwise.
*/
private boolean snapTouchPosition() {
return snapActiveThumbToValue(getValueOfTouchPosition());
}
private boolean snapActiveThumbToValue(float value) {
return snapThumbToValue(activeThumbIdx, value);
}
private boolean snapThumbToValue(int idx, float value) {
// Check if the new value equals a value that was already set.
if (Math.abs(value - values.get(idx)) < THRESHOLD) {
return false;
}
// Replace the old value with the new value of the touch position.
values.set(idx, value);
Collections.sort(values);
if (idx == activeThumbIdx) {
// Hold on to the active thumb if that's what we're tracking.
idx = values.indexOf(value);
}
activeThumbIdx = idx;
focusedThumbIdx = idx;
dispatchOnChangedFromUser(idx);
return true;
}
private float getValueOfTouchPosition() {
double position = snapPosition(touchPosition);
// We might need to invert the touch position to get the correct value.
if (ViewCompat.getLayoutDirection(this) == ViewCompat.LAYOUT_DIRECTION_RTL) {
position = 1 - position;
}
return (float) (position * (valueTo - valueFrom) + valueFrom);
}
private float valueToX(float value) {
return normalizeValue(value) * trackWidth + trackSidePadding;
}
private void ensureLabels() {
if (labelBehavior == LABEL_GONE) {
// If the label shouldn't be drawn we can skip this.
return;
}
Iterator