Events for Visual Basic 6 COM interoperability > OnWaveformScrollerMouseNotif event

Remarks

Occurs when a mouse action happens over the waveform scroller.

This event replaces the usage of the CallbackWaveformScrollerMouseNotif delegate and is only intended for usage with applications developed using Visual Basic 6 (which results unreliable when dealing with delegates and callbacks) and, in order to be enabled, requires a call to the COMEventEnable method with the nEventType parameter set to EVENT_TYPE_WAVE_SCROLL_MOUSE.

For further details about callback delegates see the How to synchronize the container application with the API tutorial.

For further details about methods of the Waveform scroller refer to the WaveformScroller object.

For a tutorial about the use of Waveform scrollers refer to the How to scroll the sound's waveform during playback tutorial.

Syntax

[Visual Basic 6]

Private Sub DjStudioApi_OnWaveformAnalyzerMouseNotif ( _

ByVal hWndWaveformScroller as Long, _

ByVal nAction as enumMouseActions, _

ByVal nFlags as Long, _

ByVal xPos as Long, _

ByVal yPos as Long _

ByVal nPressPosInPix as Long, _

ByVal nPressPosInMs as Long _

)

where "DjStudioApi" is declared in Visual Basic 6 code as:

Dim WithEvents DjStudioApi As AudioDjStudioApi.AudioDjStudioApiObj

Event Data

Parameter

Description

hWndWaveformScroller

Handle of the waveform scroller control returned by a previous call to the WaveformScroller.Create method

nAction

Mouse action type.

Supported values are the following:

Mnemonic constant	Value	Meaning
MOUSE_ACTION_LEFT_DOWN	0	Left mouse button down
MOUSE_ACTION_LEFT_UP	1	Left mouse button up
MOUSE_ACTION_LEFT_CLICK	2	Left mouse button click
MOUSE_ACTION_LEFT_DBLCLICK	3	Left mouse button double click
MOUSE_ACTION_RIGHT_DOWN	4	Right mouse button down
MOUSE_ACTION_RIGHT_UP	5	Right mouse button up
MOUSE_ACTION_RIGHT_CLICK	6	Right mouse button click
MOUSE_ACTION_RIGHT_DBLCLICK	7	Right mouse button double click
MOUSE_ACTION_MOVE	8	Mouse move
MOUSE_ACTION_MIDDLE_DOWN	9	Middle mouse button down
MOUSE_ACTION_MIDDLE_UP	10	Middle mouse button up
MOUSE_ACTION_MIDDLE_CLICK	11	Middle mouse button click
MOUSE_ACTION_MIDDLE_DBLCLICK	12	Middle mouse button double click
MOUSE_ACTION_WHEEL_SCROLL_BACK	13	Mouse wheel scroll back
MOUSE_ACTION_WHEEL_SCROLL_FORWARD	14	Mouse wheel scroll forward

nFlags

Can be a combination of the following values:

Value	Meaning
1	Set if left mouse button is down (defined as MK_LBUTTON inside the Windows SDK)
2	Set if right mouse button is down (defined as MK_RBUTTON inside the Windows SDK)
4	Set if keyboard's SHIFT key is down (defined as MK_SHIFT inside the Windows SDK)
8	Set if keyboard's CTRL key is down (defined as MK_CONTROL inside the Windows SDK)
16 (hex 10)	Set if middle mouse button is down (defined as MK_MBUTTON inside the Windows SDK)

xPos

Horizontal position, expressed in pixels respect to the waveform's client area, where the mouse generated the notification

yPos

Vertical position, expressed in pixels respect to the waveform's client area, where the mouse generated the notification

nPressPosInPix

Number representing the position expressed in pixels where the mouse button was pressed. If the mouse action should have been performed outside of the waveform's area, this parameter would be set to -1.

It's important to note that this parameter doesn't represent the horizontal position on the waveform's visible area (for this you can refer to the xPos parameter) but to the horizontal position in pixels calculated respect to the bitmap representation of the total waveform's width in pixels at the current horizontal zoom factor.

nPressPosInMs

Number representing the position expressed in milliseconds where the mouse button was pressed. If the mouse action should have been performed outside of the waveform's area, this parameter would be set to -1.