Table of Contents

Interface IVideoView

Namespace
VisioForge.Core.Types
Assembly
VisioForge.Core.dll

Defines a platform-agnostic interface for a video rendering view. This interface abstracts the underlying UI control used for displaying video, allowing the core engine to remain independent of any specific UI framework (e.g., WinForms, WPF, Android, iOS).

public interface IVideoView

Remarks

Implementations of this interface are responsible for managing a native UI element that can render video frames. It provides methods for lifecycle management, UI interaction, and event handling, including mouse input. The interface includes platform-specific sections to handle the unique requirements of different operating systems.

Methods

Attach(IMPVCVECore)

Attaches this view to a parent core engine component.

void Attach(IMPVCVECore parent)

Parameters

parent IMPVCVECore

The core engine component (e.g., MediaPlayerCore, VideoCaptureCore) to attach to.

CallInvoke(Delegate, params object[])

Executes a delegate on the UI thread of the control.

void CallInvoke(Delegate method, params object[] args)

Parameters

method Delegate

The delegate to execute.

args object[]

The arguments to pass to the delegate.

CallRefresh()

Forces the view to redraw or refresh its content.

void CallRefresh()

ClearUI()

Clears the user interface, removing any overlays or graphics.

void ClearUI()

Detach(IMPVCVECore)

Detaches this view from a parent core engine component.

void Detach(IMPVCVECore parent)

Parameters

parent IMPVCVECore

The core engine component to detach from.

GetBackgroundColor()

Gets the background color of the video view.

SKColor GetBackgroundColor()

Returns

SKColor

The background color as an SkiaSharp.SKColor.

GetHandle()

Gets the native window handle of the underlying UI control.

nint GetHandle()

Returns

nint

An IntPtr representing the window handle.

GetInvokeRequired()

Gets a value indicating whether the caller must use an invoke method when making calls to the control.

bool GetInvokeRequired()

Returns

bool

true if the call must be invoked; otherwise, false.

GetIsHandleCreated()

Gets a value indicating whether the underlying UI control's handle has been created.

bool GetIsHandleCreated()

Returns

bool

true if the handle is created; otherwise, false.

GetSize()

Gets the current size of the video view.

Size GetSize()

Returns

Size

The size as a VisioForge.Core.Types.Size structure.

GetUIEngine()

Gets the underlying UI engine being used by the view.

VideoViewUIEngine GetUIEngine()

Returns

VideoViewUIEngine

The VisioForge.Core.Types.VideoViewUIEngine used for rendering.

InvokeStart()

Signals the view that the engine has started.

void InvokeStart()

InvokeStartComplete()

Signals the view that the engine has completed its start sequence.

void InvokeStartComplete()

InvokeStop()

Signals the view that the engine has stopped.

void InvokeStop()

InvokeVideoRendererUpdate()

Triggers an update of the video renderer.

void InvokeVideoRendererUpdate()

LogDialogClear()

Clears all messages from the log dialog.

void LogDialogClear()

LogDialogClose()

Closes the log dialog if it is open.

void LogDialogClose()

LogDialogError(string)

Displays an error message in a dialog box.

void LogDialogError(string msg)

Parameters

msg string

The error message to display.

Remarks

An SDK engine calls this from inside its own error handler, which the logger raises. An implementation that logs from here - including from a catch - therefore feeds the error back into the channel that is currently reporting it, and without something to stop it the process dies of a stack overflow (issue #1173).

The SDK breaks that loop centrally, with a re-entrancy guard in the log observer, but the guard is per thread and covers only the call it is inside: a write made synchronously, on the thread this method was called on, is safe. A view that marshals to its UI thread first - DispatcherQueue.TryEnqueue, Dispatcher.BeginInvoke, Control.BeginInvoke, Task.Run - runs its catch on a fresh stack where the guard is already clear, and must not log from there. Report that failure on a channel the SDK does not observe, such as Trace.TraceError.

Keep this method cheap and make it return even when it cannot show anything.

PictureBoxCreate(int, int)

Creates a PictureBox control for video rendering.

void PictureBoxCreate(int width, int height)

Parameters

width int

The width of the PictureBox.

height int

The height of the PictureBox.

PictureBoxDestroy()

Destroys the PictureBox control.

void PictureBoxDestroy()

PictureBoxExists()

Checks if the PictureBox control currently exists.

bool PictureBoxExists()

Returns

bool

true if the PictureBox exists; otherwise, false.

PictureBoxGetImage()

Gets the current image from the PictureBox.

Bitmap PictureBoxGetImage()

Returns

Bitmap

The current bitmap image.

PictureBoxSetImage(Bitmap)

Sets the image to be displayed in the PictureBox.

void PictureBoxSetImage(Bitmap image)

Parameters

image Bitmap

The bitmap image to display.

PushMouseButtonDown(int, int, MouseButton)

Pushes a mouse button down event to the control.

void PushMouseButtonDown(int x, int y, MouseButton button)

Parameters

x int

The x-coordinate of the mouse.

y int

The y-coordinate of the mouse.

button MouseButton

The mouse button that was pressed.

PushMouseButtonUp(int, int, MouseButton)

Pushes a mouse button up event to the control.

void PushMouseButtonUp(int x, int y, MouseButton button)

Parameters

x int

The x-coordinate of the mouse.

y int

The y-coordinate of the mouse.

button MouseButton

The mouse button that was released.

PushMouseMove(int, int)

Pushes a mouse move event to the control for processing.

void PushMouseMove(int x, int y)

Parameters

x int

The x-coordinate of the mouse.

y int

The y-coordinate of the mouse.

ResizeRoundTo(int)

Resizes the video view, rounding the dimensions to a specified value.

void ResizeRoundTo(int round)

Parameters

round int

The value to round the dimensions to (e.g., 16).

SetHandle(nint)

Sets the native window handle. Used for embedding the video in a specific control.

void SetHandle(nint handle)

Parameters

handle nint

The window handle.

ShowMessage(string)

Shows a message box to the user.

MessageBoxResult ShowMessage(string message)

Parameters

message string

The message to display.

Returns

MessageBoxResult

A VisioForge.Core.Types.MessageBoxResult indicating which button the user clicked.

Remarks

Reached from an engine's error handler as well - see the remarks on VisioForge.Core.Types.IVideoView.LogDialogError(System.String).

OnMouseButtonDown

Occurs when a mouse button is pressed down over the control.

event EventHandler<MouseButtonEventArgs> OnMouseButtonDown

Event Type

EventHandler<MouseButtonEventArgs>

OnMouseButtonUp

Occurs when a mouse button is released over the control.

event EventHandler<MouseButtonEventArgs> OnMouseButtonUp

Event Type

EventHandler<MouseButtonEventArgs>

OnMouseMoved

Occurs when the mouse pointer is moved over the control.

event EventHandler<MouseMoveEventArgs> OnMouseMoved

Event Type

EventHandler<MouseMoveEventArgs>