krotos::ScrollAndZoomManager Class Reference

A class containing the logic to zoom and scroll within a timeline. More...

#include <HelperClasses.h>

Public Member Functions
void	initialise (int length)
int	getLength ()
void	resetZoomRange ()
Range< float >	getZoomWindowNormalisedToLimits ()
Range< int >	getZoomWindowRelativeToRange ()
Range< float >	getZoomWindowNormalisedToRange ()
void	repositionZoomWindow (float newStart)
void	zoom (int center, float amount)
void	drag (int diff)
int	percentMouseXToSampleXAbsolute (float percentX)
int	percentMouseXToSampleXRelative (float percentX)
int	pixelsToSamples (int pixels, int waveformScreenWidth)
bool	isSelectionEnabled ()
bool	isZoomScrollEnabled ()
void	setZoomScrollEnabled (bool newState)
void	setSelectionEnabled (bool newState)
void	setZoomRange (Range< int > newRange)
	Sets the zoom to a specific range.

Private Attributes
Range< int >	m_zoomLimits
Range< int >	m_zoomRange
Range< int >	m_zoomWindow
bool	m_selectionEnabled {true}
bool	m_zoomScrollEnabled {true}
const int	m_minimumLength {32}
int	m_length {0}

Detailed Description

A class containing the logic to zoom and scroll within a timeline.

Note, all zooming scrolling and associated range contraints are performed at an integer audio sample index level of precision. Performing these operations at a screen pixel level of accuracy would not work due to the fact that the waveform viewer may be showing a waveform which has many thousands of samples within the width of a single on-screen pixel, and the mouse moves in screen pixel increments. This accounts for the fact that the code contains a lot of casting between floats and ints, and is sometimes working in screen pixels, sometimes in sample indexes.

zoomLimits; // The range of the entire sound buffer, always starts at zero zoomRange; // The range we wish to be able to zoom and scroll within zoomWindow; // The zoomed and scrolled window into the buffer

Member Function Documentation

drag()

void krotos::ScrollAndZoomManager::drag

(

int

diff

)

Move the zoom window side to side by specifying an offset in samples.

getLength()

int krotos::ScrollAndZoomManager::getLength

(

)

Return the overall length of the buffer.

getZoomWindowNormalisedToLimits()

Range< float > krotos::ScrollAndZoomManager::getZoomWindowNormalisedToLimits

(

)

Get the current range of the zoom window, normalised to the zoom limits (the entire buffer).

getZoomWindowNormalisedToRange()

Range< float > krotos::ScrollAndZoomManager::getZoomWindowNormalisedToRange

(

)

Get the current range of the zoom window, normalised to the zoom range.

getZoomWindowRelativeToRange()

Range< int > krotos::ScrollAndZoomManager::getZoomWindowRelativeToRange

(

)

Get the current range of the zoom window, relative to the zoom range.

initialise()

void krotos::ScrollAndZoomManager::initialise

(

int

length

)

Initialse the class using the length of the buffer we wish to navigate.

isSelectionEnabled()

bool krotos::ScrollAndZoomManager::isSelectionEnabled

(

)

Return a bool indicating whether or not waveform range selection is enabled.

isZoomScrollEnabled()

bool krotos::ScrollAndZoomManager::isZoomScrollEnabled

(

)

Return a bool indicating whether or not waveform zooming and scrolling is enabled.

percentMouseXToSampleXAbsolute()

int krotos::ScrollAndZoomManager::percentMouseXToSampleXAbsolute

(

float

percentX

)

Convert a normalised position within the zoom window into an absolute sample position.

percentMouseXToSampleXRelative()

int krotos::ScrollAndZoomManager::percentMouseXToSampleXRelative

(

float

percentX

)

Convert a normalised position within the zoom window into a sample position relative to the zoom window.

pixelsToSamples()

int krotos::ScrollAndZoomManager::pixelsToSamples	(	int	pixels,
		int	waveformScreenWidth )

Convert a size in pixels to the equivalent in buffer samples.

repositionZoomWindow()

void krotos::ScrollAndZoomManager::repositionZoomWindow

(

float

newStart

)

Move the zoom window by specifying a new normalised start position.

resetZoomRange()

void krotos::ScrollAndZoomManager::resetZoomRange

(

)

Zoom fully out so the zoom window sees the entire buffer.

setSelectionEnabled()

void krotos::ScrollAndZoomManager::setSelectionEnabled

(

bool

newState

)

Set whether or not we require waveform range selection to be enabled.

setZoomRange()

void krotos::ScrollAndZoomManager::setZoomRange

(

Range< int >

newRange

)

Sets the zoom to a specific range.

Parameters

newRange

The range to set the zoom to.

setZoomScrollEnabled()

void krotos::ScrollAndZoomManager::setZoomScrollEnabled

(

bool

newState

)

Set whether or not we require waveform zooming and scrolling to be enabled.

zoom()

void krotos::ScrollAndZoomManager::zoom	(	int	center,
		float	amount )

Zoom by a specified fractional amount, centered around a specified buffer position in samples.

Member Data Documentation

m_length

int krotos::ScrollAndZoomManager::m_length {0}

private

m_minimumLength

const int krotos::ScrollAndZoomManager::m_minimumLength {32}

private

m_selectionEnabled

bool krotos::ScrollAndZoomManager::m_selectionEnabled {true}

private

m_zoomLimits

Range<int> krotos::ScrollAndZoomManager::m_zoomLimits

private

The range of the entire sound buffer, always starts at zero.

m_zoomRange

Range<int> krotos::ScrollAndZoomManager::m_zoomRange

private

The range we wish to be able to zoom and scroll within.

m_zoomScrollEnabled

bool krotos::ScrollAndZoomManager::m_zoomScrollEnabled {true}

private

m_zoomWindow

Range<int> krotos::ScrollAndZoomManager::m_zoomWindow

private

The zoomed and scrolled window into the buffer.

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The documentation for this class was generated from the following files:

• krotos_gui/components/waveform_viewer/HelperClasses.h
• krotos_gui/components/waveform_viewer/HelperClasses.cpp