/// <summary>
/// Ensures correct size of the widget.
/// </summary>
protected override void OnMeasure(int widthMeasureSpec, int heightMeasureSpec)
{
var width = 200;
if (MeasureSpecMode.Unspecified != MeasureSpec.GetMode(widthMeasureSpec))
{
width = MeasureSpec.GetSize(widthMeasureSpec);
}
var height = ThumbImage.Height
+ (ShowTextAboveThumbs ? PixelUtil.DpToPx(Context, HeightInDp) + PixelUtil.SpToPx(Context, TextSizeInSp) : 0)
+ (ThumbShadow ? ThumbShadowYOffset + _thumbShadowBlur : 0);
if (MeasureSpecMode.Unspecified != MeasureSpec.GetMode(heightMeasureSpec))
{
height = Math.Min(height, MeasureSpec.GetSize(heightMeasureSpec));
}
SetMeasuredDimension(width, height);
}
/// <summary>
/// Draws the widget on the given canvas.
/// </summary>
protected override void OnDraw(Canvas canvas)
{
base.OnDraw(canvas);
_paint.TextSize = _textSize;
_paint.SetStyle(Paint.Style.Fill);
_paint.Color = DefaultColor;
_paint.AntiAlias = true;
float minMaxLabelSize = 0;
if (ShowLabels)
{
// draw min and max labels
var minLabel = Context.GetString(Resource.String.demo_min_label);
var maxLabel = Context.GetString(Resource.String.demo_max_label);
minMaxLabelSize = Math.Max(_paint.MeasureText(minLabel), _paint.MeasureText(maxLabel));
var minMaxHeight = _textOffset + _thumbHalfHeight + (float)_textSize / 3;
if (!MinThumbTextHidden)
{
canvas.DrawText(minLabel, 0, minMaxHeight, _paint);
}
if (!MaxThumbTextHidden)
{
canvas.DrawText(maxLabel, Width - minMaxLabelSize, minMaxHeight, _paint);
}
}
_padding = _internalPad + minMaxLabelSize + _thumbHalfWidth;
// draw seek bar background line
_rect.Left = _padding;
_rect.Right = Width - _padding;
_rect.Top = _textOffset + _thumbHalfHeight - _barHeight / 2;
_rect.Bottom = _textOffset + _thumbHalfHeight + _barHeight / 2;
canvas.DrawRect(_rect, _paint);
var selectedValuesAreDefault = NormalizedMinValue <= MinDeltaForDefault &&
NormalizedMaxValue >= 1 - MinDeltaForDefault;
var colorToUseForButtonsAndHighlightedLine =
!Enabled || (!AlwaysActive && !ActivateOnDefaultValues && selectedValuesAreDefault)
? DefaultColor // default values
: ActiveColor; // non default, filter is active
// draw seek bar active range line
_rect.Left = NormalizedToScreen(NormalizedMinValue);
_rect.Right = NormalizedToScreen(NormalizedMaxValue);
_paint.Color = colorToUseForButtonsAndHighlightedLine;
canvas.DrawRect(_rect, _paint);
// draw minimum thumb (& shadow if requested) if not a single thumb control
if (!MinThumbHidden)
{
if (ThumbShadow)
{
DrawThumbShadow(NormalizedToScreen(NormalizedMinValue), canvas);
}
DrawThumb(NormalizedToScreen(NormalizedMinValue), Thumb.Lower.Equals(_pressedThumb), canvas,
selectedValuesAreDefault);
}
// draw maximum thumb & shadow (if necessary)
if (!MaxThumbHidden)
{
if (ThumbShadow)
{
DrawThumbShadow(NormalizedToScreen(NormalizedMaxValue), canvas);
}
DrawThumb(NormalizedToScreen(NormalizedMaxValue), Thumb.Upper.Equals(_pressedThumb), canvas,
selectedValuesAreDefault);
}
// draw the text if sliders have moved from default edges
if (!ShowTextAboveThumbs || (!ActivateOnDefaultValues && selectedValuesAreDefault))
{
return;
}
_paint.TextSize = _textSize;
_paint.Color = TextAboveThumbsColor;
var minText = ValueToString(GetSelectedMinValue(), Thumb.Lower);
var maxText = ValueToString(GetSelectedMaxValue(), Thumb.Upper);
var minTextWidth = _paint.MeasureText(minText);
var maxTextWidth = _paint.MeasureText(maxText);
// keep the position so that the labels don't get cut off
var minPosition = Math.Max(0f, NormalizedToScreen(NormalizedMinValue) - minTextWidth * 0.5f);
var maxPosition = Math.Min(Width - maxTextWidth,
NormalizedToScreen(NormalizedMaxValue) - maxTextWidth * 0.5f);
if (!MaxThumbHidden && !MinThumbHidden)
{
// check if the labels overlap, or are too close to each other
var spacing = PixelUtil.DpToPx(Context, TextLateralPaddingInDp);
var overlap = minPosition + minTextWidth - maxPosition + spacing;
if (overlap > 0f)
{
// we could move them the same ("overlap * 0.5f")
// but we rather move more the one which is farther from the ends, as it has more space
minPosition -= overlap * NormalizedMinValue / (NormalizedMinValue + 1 - NormalizedMaxValue);
maxPosition += overlap * (1 - NormalizedMaxValue) / (NormalizedMinValue + 1 - NormalizedMaxValue);
}
}
if (!MinThumbHidden && !MinThumbTextHidden)
{
canvas.DrawText(minText,
minPosition,
_distanceToTop + _textSize,
_paint);
}
if (!MaxThumbHidden && !MaxThumbTextHidden)
{
canvas.DrawText(maxText,
maxPosition,
_distanceToTop + _textSize,
_paint);
}
}
private void Init(Context context, IAttributeSet attrs)
{
var defaultShadowColor = Color.Argb(75, 0, 0, 0);
var defaultShadowYOffset = PixelUtil.DpToPx(context, 2);
var defaultShadowXOffset = PixelUtil.DpToPx(context, 0);
var defaultShadowBlur = PixelUtil.DpToPx(context, 2);
_distanceToTop = PixelUtil.DpToPx(context, DefaultTextDistanceToTopInDp);
if (attrs == null)
{
SetRangeToDefaultValues();
_internalPad = PixelUtil.DpToPx(context, InitialPaddingInDp);
_barHeight = PixelUtil.DpToPx(context, LineHeightInDp);
ActiveColor = DefaultDarkBlueColor;
DefaultColor = Color.Gray;
AlwaysActive = false;
ShowTextAboveThumbs = true;
TextAboveThumbsColor = Color.White;
thumbShadowColor = defaultShadowColor;
ThumbShadowXOffset = defaultShadowXOffset;
ThumbShadowYOffset = defaultShadowYOffset;
_thumbShadowBlur = defaultShadowBlur;
ActivateOnDefaultValues = false;
TextSizeInSp = DefaultTextSizeInSp;
MaterialUI = false;
}
else
{
var a = Context.ObtainStyledAttributes(attrs, Resource.Styleable.RangeSliderControl, 0, 0);
try
{
SetRangeValues(ExtractNumericValueFromAttributes(a, Resource.Styleable.RangeSliderControl_absoluteMinValue, DefaultMinimum),
ExtractNumericValueFromAttributes(a, Resource.Styleable.RangeSliderControl_absoluteMaxValue, DefaultMaximum));
ShowTextAboveThumbs = a.GetBoolean(Resource.Styleable.RangeSliderControl_valuesAboveThumbs, true);
TextAboveThumbsColor = a.GetColor(Resource.Styleable.RangeSliderControl_textAboveThumbsColor, Color.White);
MinThumbHidden = a.GetBoolean(Resource.Styleable.RangeSliderControl_minThumbHidden, false);
MaxThumbHidden = a.GetBoolean(Resource.Styleable.RangeSliderControl_maxThumbHidden, false);
ShowLabels = a.GetBoolean(Resource.Styleable.RangeSliderControl_showRangeLabels, true);
_internalPad = a.GetDimensionPixelSize(Resource.Styleable.RangeSliderControl_internalPadding, InitialPaddingInDp);
_barHeight = a.GetDimensionPixelSize(Resource.Styleable.RangeSliderControl_barHeight, LineHeightInDp);
ActiveColor = a.GetColor(Resource.Styleable.RangeSliderControl_activeColor, DefaultDarkBlueColor);
DefaultColor = a.GetColor(Resource.Styleable.RangeSliderControl_defaultColor, Color.Gray);
AlwaysActive = a.GetBoolean(Resource.Styleable.RangeSliderControl_alwaysActive, false);
StepValue = ExtractNumericValueFromAttributes(a, Resource.Styleable.RangeSliderControl_stepValue, DefaultStepValue);
StepValueContinuously = a.GetBoolean(Resource.Styleable.RangeSliderControl_stepValueContinuously, false);
var normalDrawable = a.GetDrawable(Resource.Styleable.RangeSliderControl_thumbNormal);
if (normalDrawable != null)
{
DefaultThumbImage = BitmapUtil.DrawableToBitmap(normalDrawable);
}
var disabledDrawable = a.GetDrawable(Resource.Styleable.RangeSliderControl_thumbDisabled);
if (disabledDrawable != null)
{
DefaultThumbDisabledImage = BitmapUtil.DrawableToBitmap(disabledDrawable);
}
var pressedDrawable = a.GetDrawable(Resource.Styleable.RangeSliderControl_thumbPressed);
if (pressedDrawable != null)
{
DefaultThumbPressedImage = BitmapUtil.DrawableToBitmap(pressedDrawable);
}
ThumbShadow = a.GetBoolean(Resource.Styleable.RangeSliderControl_thumbShadow, false);
thumbShadowColor = a.GetColor(Resource.Styleable.RangeSliderControl_thumbShadowColor, defaultShadowColor);
ThumbShadowXOffset = a.GetDimensionPixelSize(Resource.Styleable.RangeSliderControl_thumbShadowXOffset, defaultShadowXOffset);
ThumbShadowYOffset = a.GetDimensionPixelSize(Resource.Styleable.RangeSliderControl_thumbShadowYOffset, defaultShadowYOffset);
_thumbShadowBlur = a.GetDimensionPixelSize(Resource.Styleable.RangeSliderControl_thumbShadowBlur, defaultShadowBlur);
ActivateOnDefaultValues = a.GetBoolean(Resource.Styleable.RangeSliderControl_activateOnDefaultValues, false);
TextSizeInSp = a.GetInt(Resource.Styleable.RangeSliderControl_textSize, DefaultTextSizeInSp);
MaterialUI = a.GetBoolean(Resource.Styleable.RangeSliderControl_materialUI, false);
}
finally
{
a.Recycle();
}
}
SetBarHeight(_barHeight);
// make RangeSliderControl focusable. This solves focus handling issues in case EditText widgets are being used along with the RangeSliderControl within ScrollViews.
Focusable = true;
FocusableInTouchMode = true;
_scaledTouchSlop = ViewConfiguration.Get(Context).ScaledTouchSlop;
UpdateThumbImages();
}
private void UpdateTextOffset()
{
_textOffset = _showTextAboveThumbs
? _textSize + PixelUtil.DpToPx(Context, DefaultTextDistanceToButtonInDp) + _distanceToTop
: 0;
}