A discrete value that can't blend, like a text or an icon: on a change the previous value fades out while the new one fades in, over a Transition found exactly like Animated's (layout "transition" by property name, preset, inline spec). More...

#include <gin_animated.h>

Inheritance diagram for Crossfade< T >:

Public Member Functions
	Crossfade (juce::Component &owner, const juce::String &property={}, T initial=T())
const T &	getCurrent () const
	The incoming value, the only one once the fade ends.
const T &	getPrevious () const
	The outgoing value; equals getCurrent() when no fade runs.
float	getProgress () const
	0 shows only the previous value, 1 only the current one
template<typename PaintFn>
void	draw (PaintFn &&paintOne) const
	Paints both sides of the fade with your own drawing: calls paintOne (value, opacity) for the previous value at 1 - progress and the current one at progress, skipping a side at opacity 0.
void	setValue (T newValue)
	Jumps to the value, stopping any fade.
void	updateTarget (T newValue)
	Changes the incoming value without restarting a running fade, e.g.
void	setTarget (T newTarget)
	Fades to the value with the owner's transition for the property.
void	setTarget (T newTarget, const juce::String &nameOrSpec)
	Fades to the value with a preset name (looked up from the owner up), an inline spec like "150 inOutQuad" or "none".
void	setTarget (T newTarget, const Transition &t)
	Fades to the value with an explicit Transition.
Public Member Functions inherited from AnimatedBase
	AnimatedBase (juce::Component &owner, const juce::String &property)
virtual	~AnimatedBase ()
bool	isAnimating () const
	True while a transition runs.
juce::Component *	getOwner () const
	The owning component, nullptr once it was deleted.
const juce::String &	getProperty () const
	The name the layout's "transition" entries know this value by.
Transition	getTransition () const
	The transition setTarget (value) uses: the owner's for the property, see Transition::forProperty.

Additional Inherited Members
Public Attributes inherited from AnimatedBase
std::function< void()>	onChange
	Called on every change of the current value (each animation step, and jumps), after the owner was asked to repaint.
Protected Member Functions inherited from AnimatedBase
bool	start (const Transition &t)
	Returns false when the change has to apply at once: an instant transition or an owner not on screen.
void	stop ()
void	changed ()
virtual void	valueChanged ()
	For subclasses that apply the value somewhere: called on every change, before onChange.
float	getLastProgress () const
	The eased progress of the latest step of the running transition.

Detailed Description

template<typename T>
class Crossfade< T >

A discrete value that can't blend, like a text or an icon: on a change the previous value fades out while the new one fades in, over a Transition found exactly like Animated's (layout "transition" by property name, preset, inline spec).

Painting draws getPrevious() at an opacity of 1 - getProgress() and getCurrent() at getProgress(), or uses the drawText / drawIcon helpers which do just that. T needs copy assignment and operator==; juce::String and juce::Path are the usual ones.

A new target while a fade runs restarts it from 0, with the value that showed more so far as the one fading out. updateTarget() changes the incoming value without a restart.

// layout json: { "id": "status", "transition": { "caption": "150 inOutQuad" } }
class Status : public juce::Component
{
public:
    void setOnline (bool online)    { caption.setTarget (online ? "Online" : "Offline"); }
 
    void paint (juce::Graphics& g) override
    {
        gin::drawText (g, caption, getLocalBounds().toFloat(), juce::Font (juce::FontOptions (15.0f)),
                       juce::Colours::white, juce::Justification::centred);
    }
 
private:
    gin::Crossfade<juce::String> caption { *this, "caption", "Offline" };
};

See also: Animated, drawText, drawIcon

Constructor & Destructor Documentation

◆ Crossfade()

template<typename T>

Crossfade< T >::Crossfade	(	juce::Component &	owner,
		const juce::String &	property = {},
		T	initial = T() )

Parameters

owner	The component that repaints on every step and whose layout transitions apply
property	The name the layout's "transition" object knows this value by
initial	The starting value, shown alone

Member Function Documentation

◆ getCurrent()

template<typename T>

const T & Crossfade< T >::getCurrent ( ) const

The incoming value, the only one once the fade ends.

◆ getPrevious()

template<typename T>

const T & Crossfade< T >::getPrevious ( ) const

The outgoing value; equals getCurrent() when no fade runs.

◆ getProgress()

template<typename T>

float Crossfade< T >::getProgress ( ) const

0 shows only the previous value, 1 only the current one

◆ draw()

template<typename T>

template<typename PaintFn>

void Crossfade< T >::draw ( PaintFn && paintOne ) const

Paints both sides of the fade with your own drawing: calls paintOne (value, opacity) for the previous value at 1 - progress and the current one at progress, skipping a side at opacity 0.

Multiply your colours' alpha by the opacity.

weight.draw ([&] (int w, float opacity)
{
    g.setColour (juce::Colours::white.withMultipliedAlpha (opacity));
    g.setFont (juce::FontOptions (14.0f).withStyle (w > 500 ? "Bold" : "Regular"));
    g.drawText (label, area, juce::Justification::centred);
});