Method SetContinuousScrollMode

SetContinuousScrollMode(Int32, Int32, Int32, Int32, String, Int32, Int32)

Sets the device to the continuous scroll mode.

Declaration

Error SetContinuousScrollMode(int numberOfPages, int numberOfTiles, int startTileNumber, int startTileOffset, string buttonText, int tileWidth, int tileHeight = 702)

Parameters

Type	Name	Description
System.Int32	numberOfPages	The number of pages of the document.
System.Int32	numberOfTiles	The number of tiles the document is to be split up into.
System.Int32	startTileNumber	This tile number is requested first.
System.Int32	startTileOffset	Scrolls the first tile down.
System.String	buttonText	The text inside the button.
System.Int32	tileWidth	The width of a tile /pixels. Recommended width: 992.
System.Int32	tileHeight	The height of a tile /pixels. Recommended height: 702.

Returns

Type	Description
Error	Error

Remarks

The continuous scroll mode is used for viewing multipage documents split up into several tiles. These tiles form a vertical stack of the document that can be scrolled with the pen.

When started, the device is requesting tiles through the ScrollEvent.

The device will never request for tile numbers bigger than the total numberOfTiles.

When one is scrolling fast the device is asking for a tile that corresponds to a page number. Then IsPageNumber is true and you have to determine the corresponding tile number for that page number and set it with

SetContinuousScrollTileNumber(Int32, Int32, Int32).

These tile requests have to be fulfilled by uploading tiles by means of

UploadContinuousScrollTile(Bitmap, Int32, Int32, Int32)

The mode has one button labeled with the buttonText. Clicking it triggers a ButtonEvent while the device shows an hourglass and waits for further commands.

Whether a device supports the continuous scroll feature can be queried with DeviceProperties.IFeatures.ContinuousScrollingSupport.

Examples

The following example initiates the continuous scroll mode with dynamically created tiles which have numbers written in them. The example assumes that each page of the document is composed of two tiles. The button is used for stopping the demonstration.

C#

int numberOfPages = 32;
int numberOfTiles = 2 * numberOfPages;
int startTileNumber = 7;
int width = 992; //recommended
int height = 702; //recommended
int startTileOffset = height / 2;

bool running = true;
driver.ButtonEvent += (object sender, ButtonEventArgs e) =>
{
    driver.SetCustomerLogoMode();
    running = false;
};
driver.ScrollEvent += (object sender, ScrollEventArgs e) =>
{
    int pageNumber, tileNumber;
    if (e.IsPageNumber)
    {
        pageNumber = e.RequestedNumber;
        tileNumber = 2 * pageNumber;
        driver.SetContinuousScrollTileNumber(tileNumber, numberOfTiles, 0);
        return;
    }
    else
    {
        tileNumber = e.RequestedNumber;
        pageNumber = (tileNumber + tileNumber % 2) / 2;
    }

    Bitmap bitmap = GetTile(tileNumber, width, height);
    driver.UploadContinuousScrollTile(bitmap, tileNumber, pageNumber, numberOfTiles);
};

Error error = driver.SetContinuousScrollMode(numberOfPages, numberOfTiles,
    startTileNumber, startTileOffset, "Click to exit.", width);

while (running)
{
    Thread.Sleep(500);
}


Bitmap GetTile(int tileNumber, int width, int height)
{
    int magicHeight = 702;
    float emSize = 16.0f;
    Rectangle box = new Rectangle(0, 0, width, height);
    Bitmap bitmap = new Bitmap(box.Width, box.Height);
    using Graphics g = Graphics.FromImage(bitmap);
    g.Clear(Color.White);
    g.DrawString($"Tile {tileNumber}.",
        new Font(FontFamily.GenericSansSerif, emSize, FontStyle.Regular),
        Brushes.Black, new PointF(width / 2, height / 2));
    g.DrawRectangle(new Pen(Brushes.Blue, emSize), box);
    g.DrawLine(new Pen(Brushes.Red, emSize), 0, magicHeight, width, magicHeight);
    return bitmap;
}

A similar program in

VB.NET

Dim running As Boolean = True
Dim numberOfPages As Integer = 32
Dim numberOfTiles As Integer = 2 * numberOfPages
Dim startTileNumber As Integer = 7
Dim width As Integer = 992 'recommended
Dim height As Integer = 702 'recommended

Sub ScrollThroughNumberedTiles()
    Dim r As Sig.DeviceAPI.Error
    Dim startTileOffset As Integer = height / 2
    r = driver.SetContinuousScrollMode(numberOfPages, numberOfTiles,
        startTileNumber, startTileOffset, "Click to exit.", width)
    While (running)
        Thread.Sleep(500)
    End While
End Sub

Sub HandleScrollEvent(sender As Object, e As ScrollEventArgs) Handles driver.ScrollEvent
    Dim pageNumber, tileNumber As Integer
    If (e.IsPageNumber) Then

        pageNumber = e.RequestedNumber
        tileNumber = 2 * pageNumber
        driver.SetContinuousScrollTileNumber(tileNumber, numberOfTiles, 0)
        Return
    Else
        tileNumber = e.RequestedNumber
        pageNumber = (tileNumber + tileNumber Mod 2) / 2
    End If
    driver.UploadContinuousScrollTile(GetTile(tileNumber, width, height), tileNumber, pageNumber, numberOfTiles)
End Sub

Sub HandleButtonEvent(sender As Object, e As ButtonEventArgs) Handles driver.ButtonEvent
    driver.SetCustomerLogoMode()
    running = False
End Sub

Function GetTile(tileNumber As Integer, width As Integer, height As Integer) As Bitmap
    Dim magicHeight As Integer = 702
    Dim emSize As Single = 16.0F
    Dim box As Rectangle = New Rectangle(0, 0, width, height)
    Dim bitmap As Bitmap = New Bitmap(box.Width, box.Height)
    Using g As Graphics = Graphics.FromImage(bitmap)
        g.Clear(Color.White)
        g.DrawString($"Tile {tileNumber}.",
            New Font(FontFamily.GenericSansSerif, emSize, FontStyle.Regular),
            Brushes.Black, New PointF(width / 2, height / 2))
        g.DrawRectangle(New Pen(Brushes.Blue, emSize), box)
        g.DrawLine(New Pen(Brushes.Red, emSize), 0, magicHeight, width, magicHeight)
        Return bitmap
    End Using
End Function