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# Class Element

Element is the abstract interface used to access graphical elements used to build the display list.

Just like many other classes in PDFNet (e.g. ColorSpace, Font, Annot, etc), Element class follows the composite design pattern. This means that all Elements are accessed through the same interface, but depending on the Element type (that can be obtained using GetType()), only methods related to that type can be called. For example, if GetType() returns e_image, it is illegal to call a method specific to another Element type (i.e. a call to a text specific GetTextData() will throw an Exception).

##### Inheritance

object
Element

##### Inherited Members

object.Equals(object)
object.Equals(object, object)
object.GetHashCode()
object.MemberwiseClone()
object.ReferenceEquals(object, object)
object.ToString()

###### Namespace: pdftron.PDF

###### Assembly: PDFTronDotNet.dll

##### Syntax

    public class Element

### Methods

#### GetBBox(Rect)

Obtains the bounding box for a graphical element.

Calculates the bounding box for a graphical element (i.e. an Element that belongs to one of following types: e_path, e_text, e_image, e_inline_image, e_shading e_form). The returned bounding box is guaranteed to encompass the Element, but is not guaranteed to be the smallest box that could contain the element. For example, for Bezier curves the bounding box will enclose all control points, not just the curve itself.

##### Declaration

    public bool GetBBox(Rect bbox)

##### Parameters

Type | Name | Description
--- | --- | ---
Rect | bbox | (Filled by the method) A reference to a rectangle specifying the bounding box of Element (a rectangle that surrounds the entire element). The coordinates are represented in the default PDF page coordinate system and are using units called points ( 1 point = 1/72 inch = 2.54 /72 centimeter). The bounding box already accounts for the effects of current transformation matrix (CTM), text matrix, font size, and other properties in the graphics state. If this is a non-graphical element (i.e. the method returns false) the bounding box is undefined.

##### Returns

Type | Description
--- | ---
bool | Rect if this is a graphical element and the bounding box can be calculated; null for non-graphical elements which don't have bounding box. The coordinates are represented in the default PDF page coordinate system and are using units called points ( 1 point = 1/72 inch = 2.54 /72 centimeter). The bounding box already accounts for the effects of current transformation matrix (CTM), text matrix, font size, and other properties in the graphics state. If this is a non-graphical element (i.e. the method returns false) the bounding box is undefined.

##### Exceptions

Type | Condition
--- | ---
PDFNetException | PDFNetException the PDFNet exception

#### GetBitsPerComponent()

Gets the bits per component.

##### Declaration

    public int GetBitsPerComponent()

##### Returns

Type | Description
--- | ---
int | the number of bits used to represent each color component. Only a single value may be specified; the number of bits is the same for all color components. Valid values are 1, 2, 4, and 8.

##### Exceptions

Type | Condition
--- | ---
PDFNetException | PDFNetException the PDFNet exception

#### GetCTM()

Gets the cTM.

##### Declaration

    public Matrix2D GetCTM()

##### Returns

Type | Description
--- | ---
Matrix2D | current transformation matrix (ctm) that maps coordinates to the initial user space.

##### Exceptions

Type | Condition
--- | ---
PDFNetException | PDFNetException the PDFNet exception

#### GetCharIterator()

Gets the char iterator.

##### Declaration

    public CharIterator GetCharIterator()

##### Returns

Type | Description
--- | ---
CharIterator | a CharIterator addressing the first CharData element in the text run. CharIterator points to CharData. CharData is a data structure that contains the char_code number (used to retrieve glyph outlines, to map to Unicode, etc.), character positioning information (x, y), and the number of bytes taken by the character within the text buffer.

##### Remarks

CharIterator follows the standard STL forward-iterator interface.
An example of how to use CharIterator.

    for (CharIterator itr = element.GetCharIterator(); itr.HasNext(); itr.Next()) {
    unsigned int char_code = itr.Current().char_code;
    double char_pos_x = itr.Current().x;
    double char_pos_y = itr.Current().y;
    }

Character positioning information (x, y) is represented in text space.

In order to get the positioning in the user space, the returned value should be scaled using the text matrix (GetTextMatrix()) and the current transformation matrix (GetCTM()). See section 4.2 'Other Coordinate Spaces' in PDF Reference Manual for details and PDFNet FAQ - "How do I get absolute/relative text and character positioning?".

whithin a text run a character may occupy more than a single byte (e.g. in case of composite/Type0 fonts). The role of CharIterator/CharData is to provide a uniform and easy to use inteface to access character information.

##### Exceptions

Type | Condition
--- | ---
PDFNetException | PDFNetException the PDFNet exception

#### GetComponentNum()

Gets the component number.

##### Declaration

    public int GetComponentNum()

##### Returns

Type | Description
--- | ---
int | the number of color components per sample.

##### Exceptions

Type | Condition
--- | ---
PDFNetException | PDFNetException the PDFNet exception

#### GetDecodeArray()

Gets the decode array.

##### Declaration

    public Obj GetDecodeArray()

##### Returns

Type | Description
--- | ---
Obj | Decode array or NULL if the paramter is not specified. A decode object is an array of numbers describing how to map image samples into the range of values appropriate for the image's color space . If ImageMask is true, the array must be either [0 1] or [1 0]; otherwise, its length must be twice the number of color components required by ColorSpace. Default value depends on the color space, See Table 4.36 in PDF Ref. Manual.

##### Exceptions

Type | Condition
--- | ---
PDFNetException | PDFNetException the PDFNet exception

#### GetGState()

Gets the g state.

##### Declaration

    public GState GetGState()

##### Returns

Type | Description
--- | ---
GState | GState of this Element

##### Exceptions

Type | Condition
--- | ---
PDFNetException | PDFNetException the PDFNet exception

#### GetImageColorSpace()

Gets the image color space.

##### Declaration

    public ColorSpace GetImageColorSpace()

##### Returns

Type | Description
--- | ---
ColorSpace | The SDF object representing the color space in which image are specified or NULL if: the image is an image mask or is compressed using JPXDecode with missing ColorSpace entry in image dictionary. The returned color space may be any type of color space except Pattern.

##### Exceptions

Type | Condition
--- | ---
PDFNetException | PDFNetException the PDFNet exception

#### GetImageData()

Gets the image data.

##### Declaration

    public Filter GetImageData()

##### Returns

Type | Description
--- | ---
Filter | A stream (filter) containing decoded image data

##### Exceptions

Type | Condition
--- | ---
PDFNetException | PDFNetException the PDFNet exception

#### GetImageDataSize()

Gets the image data size.

##### Declaration

    public int GetImageDataSize()

##### Returns

Type | Description
--- | ---
int | the size of image data in bytes

##### Exceptions

Type | Condition
--- | ---
PDFNetException | PDFNetException the PDFNet exception

#### GetImageHeight()

Gets the image height.

##### Declaration

    public int GetImageHeight()

##### Returns

Type | Description
--- | ---
int | the height of the image, in samples.

##### Exceptions

Type | Condition
--- | ---
PDFNetException | PDFNetException the PDFNet exception

#### GetImageRenderingIntent()

Gets the image rendering intent.

##### Declaration

    public GState.RenderingIntent GetImageRenderingIntent()

##### Returns

Type | Description
--- | ---
GState.RenderingIntent | The color rendering intent to be used in rendering the image.

##### Exceptions

Type | Condition
--- | ---
PDFNetException | PDFNetException the PDFNet exception

#### GetImageWidth()

Gets the image width.

##### Declaration

    public int GetImageWidth()

##### Returns

Type | Description
--- | ---
int | the width of the image, in samples.

##### Exceptions

Type | Condition
--- | ---
PDFNetException | PDFNetException the PDFNet exception

#### GetMCPropertyDict()

Gets the mC property dict.

##### Declaration

    public Obj GetMCPropertyDict()

##### Returns

Type | Description
--- | ---
Obj | a dictionary containing the property list or NULL if property dictionary is not present.

##### Remarks

the function automatically looks under Properties sub-dictionary of the current resource dictionary if the dictionary is not in-line. Therefore you can assume that returned Obj is dictionary if it is not NULL.

##### Exceptions

Type | Condition
--- | ---
PDFNetException | PDFNetException the PDFNet exception

#### GetMCTag()

Gets the mC tag.

##### Declaration

    public Obj GetMCTag()

##### Returns

Type | Description
--- | ---
Obj | a tag is a name object indicating the role or significance of the marked content point/sequence.

##### Exceptions

Type | Condition
--- | ---
PDFNetException | PDFNetException the PDFNet exception

#### GetMask()

Gets the mask.

##### Declaration

    public Obj GetMask()

##### Returns

Type | Description
--- | ---
Obj | an image XObject defining an image mask to be applied to this image (See 'Explicit Masking', 4.8.5), or an array specifying a range of colors to be applied to it as a color key mask (See 'Color Key Masking'). If IsImageMask() return true, this method will return NULL.

##### Exceptions

Type | Condition
--- | ---
PDFNetException | PDFNetException the PDFNet exception

#### GetNewTextLineOffset(ref double, ref double)

Gets the offset (out_x, out_y) to the start of the current line relative to the beginning of the previous line.

out_x and out_y are numbers expressed in unscaled text space units. The returned numbers correspond to the arguments of 'Td' operator.

##### Declaration

    public void GetNewTextLineOffset(ref double out_x, ref double out_y)

##### Parameters

Type | Name | Description
--- | --- | ---
double | out_x | x coordinate of the text line offset
double | out_y | y coordinate of the text line offset

##### Exceptions

Type | Condition
--- | ---
PDFNetException | PDFNetException the PDFNet exception

#### GetParentStructElement()

Gets the parent logical structure element

##### Declaration

    public SElement GetParentStructElement()

##### Returns

Type | Description
--- | ---
SElement | Parent logical structure element (such as 'span' or 'paragraph'). If the Element is not associated with any structure element, the returned SElement will not be valid (i.e. selem.IsValid() -> false).

##### Exceptions

Type | Condition
--- | ---
PDFNetException | PDFNetException the PDFNet exception

#### GetPathData()

Get the PathData stored by the path element.

##### Declaration

    public PathData GetPathData()

##### Returns

Type | Description
--- | ---
PathData | The PathData which contains the operators and corresponding point data.

##### Exceptions

Type | Condition
--- | ---
PDFNetException | PDFNetException the PDFNet exception

#### GetPosAdjustment()

Gets the pos adjustment.

##### Declaration

    public double GetPosAdjustment()

##### Returns

Type | Description
--- | ---
double | The number used to adjust text matrix in horizontal direction when drawing text. The number is expressed in thousandths of a unit of text space. The returned number corresponds to a number value within TJ array. For 'Tj' text strings the returned value is always 0.

##### Remarks

because CharIterator positioning information already accounts for TJ adjustments this method is rarely used.

##### Exceptions

Type | Condition
--- | ---
PDFNetException | PDFNetException the PDFNet exception

#### GetShading()

Gets the shading.

##### Declaration

    public Shading GetShading()

##### Returns

Type | Description
--- | ---
Shading | the SDF object of the Shading object.

##### Exceptions

Type | Condition
--- | ---
PDFNetException | PDFNetException the PDFNet exception

#### GetStructMCID()

Gets the struct MCID.

##### Declaration

    public int GetStructMCID()

##### Returns

Type | Description
--- | ---
int | Marked Content Identifier (MCID) for this Element or a negative number if the element is not assigned an identifier/MCID. Marked content identifier can be used to associate an Element with logical structure element that refers to the Element.

##### Exceptions

Type | Condition
--- | ---
PDFNetException | PDFNetException the PDFNet exception

#### GetTextData()

Gets the text data.

##### Declaration

    public byte[] GetTextData()

##### Returns

Type | Description
--- | ---
byte[] | a pointer to the internal text buffer for this text element.

##### Remarks

GetTextData() returns the raw text data and not a Unicode string. In PDF text can be encoded using various encoding schemes so it is necessary to consider Font encoding while processing the content of this buffer. Most of the time GetTextString() is what you are looking for instead.

##### Exceptions

Type | Condition
--- | ---
PDFNetException | PDFNetException the PDFNet exception

#### GetTextDataSize()

Gets the size of the internal text buffer returned in GetTextData().

##### Declaration

    public int GetTextDataSize()

##### Returns

Type | Description
--- | ---
int | the size of the internal text buffer returned in GetTextData().

#### GetTextLength()

Gets the text length.

##### Declaration

    public double GetTextLength()

##### Returns

Type | Description
--- | ---
double | The text advance distance in text space. The total sum of all of the advance values from rendering all of the characters within this element, including the advance value on the glyphs, the effect of properties such as 'char-spacing', 'word-spacing' and positioning adjustments on 'TJ' elements.

##### Remarks

Computed text length is represented in text space. In order to get the length of the text run in the user space, the returned value should be scaled using the text matrix (GetTextMatrix()) and the current transformation matrix (GetCTM()). See section 4.2 'Other Coordinate Spaces' in PDF Reference Manual for details.

##### Exceptions

Type | Condition
--- | ---
PDFNetException | PDFNetException the PDFNet exception

#### GetTextMatrix()

Gets the text matrix.

##### Declaration

    public Matrix2D GetTextMatrix()

##### Returns

Type | Description
--- | ---
Matrix2D | a reference to the current text matrix (Tm).

##### Exceptions

Type | Condition
--- | ---
PDFNetException | PDFNetException the PDFNet exception

#### GetTextString()

Gets the text string.

##### Declaration

    public string GetTextString()

##### Returns

Type | Description
--- | ---
string | a pointer to Unicode string for this text Element. The function maps character codes to Unicode array defined by Adobe Glyph List (http://partners.adobe.com/asn/developer/type/glyphlist.txt).

##### Remarks

In PDF text can be encoded using various encoding schemes and in some cases it is not possible to extract Unicode encoding. If it is not possible to map charcode to Unicode the function will map a character to undefined code, 0xFFFD. This code is defined in private Unicode range.

    If you would like to map raw text to Unicode (or some other encoding)
    yourself use CharIterators returned by CharBegin()/CharEnd() and
    PDF::Font code mapping methods.

    The string owner is the current element (i.e. ElementReader or ElementBuilder).

##### Exceptions

Type | Condition
--- | ---
PDFNetException | PDFNetException the PDFNet exception

#### GetType()

Gets the type.

##### Declaration

    public Element.Type GetType()

##### Returns

Type | Description
--- | ---
Element.Type | the current element type.

##### Exceptions

Type | Condition
--- | ---
PDFNetException | PDFNetException the PDFNet exception

#### GetXObject()

Gets the x object.

##### Declaration

    public Obj GetXObject()

##### Returns

Type | Description
--- | ---
Obj | the SDF object of the Image/Form object.

##### Exceptions

Type | Condition
--- | ---
PDFNetException | PDFNetException the PDFNet exception

#### HasTextMatrix()

Checks for text matrix.

##### Declaration

    public bool HasTextMatrix()

##### Returns

Type | Description
--- | ---
bool | true if this element is directly associated with a text matrix (that is Tm operator is just before this text element) or false if the text matrix is default or is inherited from previous text elements.

##### Exceptions

Type | Condition
--- | ---
PDFNetException | PDFNetException the PDFNet exception

#### IsClipWindingFill()

Checks if is clip winding fill.

##### Declaration

    public bool IsClipWindingFill()

##### Returns

Type | Description
--- | ---
bool | true if the current clip path is using non-zero winding rule, or false for even-odd rule.

##### Exceptions

Type | Condition
--- | ---
PDFNetException | PDFNetException the PDFNet exception

#### IsClippingPath()

Checks if is clipping path.

##### Declaration

    public bool IsClippingPath()

##### Returns

Type | Description
--- | ---
bool | true if the current path element is a clipping path and should be added to clipping path stack.

##### Exceptions

Type | Condition
--- | ---
PDFNetException | PDFNetException the PDFNet exception

#### IsFilled()

Checks if is filled.

##### Declaration

    public bool IsFilled()

##### Returns

Type | Description
--- | ---
bool | true if the current path element should be filled

##### Exceptions

Type | Condition
--- | ---
PDFNetException | PDFNetException the PDFNet exception

#### IsImageInterpolate()

Checks if is image interpolate.

##### Declaration

    public bool IsImageInterpolate()

##### Returns

Type | Description
--- | ---
bool | a boolean indicating whether image interpolation is to be performed.

##### Exceptions

Type | Condition
--- | ---
PDFNetException | PDFNetException the PDFNet exception

#### IsImageMask()

Checks if is image mask.

##### Declaration

    public bool IsImageMask()

##### Returns

Type | Description
--- | ---
bool | a boolean indicating whether the inline image is to be treated as an image mask.

##### Exceptions

Type | Condition
--- | ---
PDFNetException | PDFNetException the PDFNet exception

#### IsOCVisible()

Checks if is oC visible.

##### Declaration

    public bool IsOCVisible()

##### Returns

Type | Description
--- | ---
bool | true if this element is visible in the optional-content context (OCG::Context). The method considers the context's current OCMD stack, the group ON-OFF states, the non-OC drawing status, the drawing and enumeration mode, and the intent. When enumerating page content, OCG::Context can be passed as a parameter in ElementReader.Begin() method. When using PDFDraw, PDFRasterizer or PDFViewCtrl class to render PDF pages use SetOCGContext() method to select an OC context.

##### Exceptions

Type | Condition
--- | ---
PDFNetException | PDFNetException the PDFNet exception

#### IsStroked()

Checks if is stroked.

##### Declaration

    public bool IsStroked()

##### Returns

Type | Description
--- | ---
bool | true if the current path element should be stroked

##### Exceptions

Type | Condition
--- | ---
PDFNetException | PDFNetException the PDFNet exception

#### IsWindingFill()

Checks if is winding fill.

##### Declaration

    public bool IsWindingFill()

##### Returns

Type | Description
--- | ---
bool | true if the current path should be filled using non-zero winding rule, or false if the path should be filled using even-odd rule. According non-zero winding rule, you can determine whether a test point is inside or outside a closed curve as follows: Draw a line from a test point to a point that is distant from the curve. Count the number of times the curve crosses the test line from left to right, and count the number of times the curve crosses the test line from right to left. If those two numbers are the same, the test point is outside the curve; otherwise, the test point is inside the curve. According to even-odd rule, you can determine whether a test point is inside or outside a closed curve as follows: Draw a line from the test point to a point that is distant from the curve. If that line crosses the curve an odd number of times, the test point is inside the curve; otherwise, the test point is outside the curve.

##### Exceptions

Type | Condition
--- | ---
PDFNetException | PDFNetException the PDFNet exception

#### SetClipWindingFill(bool)

Sets clipping path's fill rule.

##### Declaration

    public void SetClipWindingFill(bool winding_rule)

##### Parameters

Type | Name | Description
--- | --- | ---
bool | winding_rule | if winding_rule is true clipping should use non-zero winding rule, or false for even-odd rule.

##### Exceptions

Type | Condition
--- | ---
PDFNetException | PDFNetException the PDFNet exception

#### SetNewTextLineOffset(double, double)

Sets the offset (dx, dy) to the start of the current line relative to the beginning of the previous line.

##### Declaration

    public void SetNewTextLineOffset(double dx, double dy)

##### Parameters

Type | Name | Description
--- | --- | ---
double | dx | the dx
double | dy | the dy

##### Exceptions

Type | Condition
--- | ---
PDFNetException | PDFNetException the PDFNet exception

#### SetPathClip(bool)

Indicate whether the path is a clipping path or non-clipping path.

##### Declaration

    public void SetPathClip(bool clip)

##### Parameters

Type | Name | Description
--- | --- | ---
bool | clip | the new path clip

##### Exceptions

Type | Condition
--- | ---
PDFNetException | PDFNetException the PDFNet exception

#### SetPathData(PathData)

Set the PathData of this element. The PathData contains the array of points stored by the element and the array of path segment types.

##### Declaration

    public void SetPathData(PathData data)

##### Parameters

Type | Name | Description
--- | --- | ---
PathData | data | The new path data.

##### Exceptions

Type | Condition
--- | ---
PDFNetException | PDFNetException the PDFNet exception

#### SetPathFill(bool)

Indicate whether the path should be filled.

##### Declaration

    public void SetPathFill(bool fill)

##### Parameters

Type | Name | Description
--- | --- | ---
bool | fill | the new path fill

##### Exceptions

Type | Condition
--- | ---
PDFNetException | PDFNetException the PDFNet exception

#### SetPathStroke(bool)

Indicate whether the path should be stroked.

##### Declaration

    public void SetPathStroke(bool stroke)

##### Parameters

Type | Name | Description
--- | --- | ---
bool | stroke | the new path stroke

##### Exceptions

Type | Condition
--- | ---
PDFNetException | PDFNetException the PDFNet exception

#### SetPosAdjustment(double)

Sets the pos adjustment.

##### Declaration

    public void SetPosAdjustment(double adjust)

##### Parameters

Type | Name | Description
--- | --- | ---
double | adjust | the new pos adjustment

##### Exceptions

Type | Condition
--- | ---
PDFNetException | PDFNetException the PDFNet exception

#### SetTextData(byte[], int)

GetTextString() maps the raw text directly into Unicode (as specified by Adobe Glyph List (AGL) ). Even if you would prefer to decode text yourself it is more convenient to use CharIterators returned by CharBegin()/CharEnd() and PDF::Font code mapping methods.

##### Declaration

    public void SetTextData(byte[] text_data, int text_data_size)

##### Parameters

Type | Name | Description
--- | --- | ---
byte[] | text_data | a pointer to a buffer containing text.
int | text_data_size | size of the cli::array

##### Remarks

the buffer owner is the current element (i.e. ElementReader or ElementBuilder). Set the text data for the current e_text Element.

##### Exceptions

Type | Condition
--- | ---
PDFNetException | PDFNetException the PDFNet exception

#### SetTextMatrix(double, double, double, double, double, double)

Sets the text matrix for a text element. This method accepts text transformation matrix components directly.

A transformation matrix in PDF is specified by six numbers, usually in the form of an array containing six elements. In its most general form, this array is denoted [a b c d h v]; it can represent any linear transformation from one coordinate system to another. For more information about PDF matrices please refer to section 4.2.2 'Common Transformations' in PDF Reference Manual, and to documentation for Matrix2D class.

##### Declaration

    public void SetTextMatrix(double a, double b, double c, double d, double h, double v)

##### Parameters

Type | Name | Description
--- | --- | ---
double | a | horizontal 'scaling' component of the new text matrix.
double | b | 'rotation' component of the new text matrix.
double | c | 'rotation' component of the new text matrix.
double | d | vertical 'scaling' component of the new text matrix.
double | h | horizontal translation component of the new text matrix.
double | v | vertical translation component of the new text matrix.

##### Exceptions

Type | Condition
--- | ---
PDFNetException | PDFNetException the PDFNet exception

#### SetTextMatrix(Matrix2D)

Sets the text matrix for a text element.

##### Declaration

    public void SetTextMatrix(Matrix2D mtx)

##### Parameters

Type | Name | Description
--- | --- | ---
Matrix2D | mtx | The new text matrix for this text element

##### Exceptions

Type | Condition
--- | ---
PDFNetException | PDFNetException the PDFNet exception

#### SetWindingFill(bool)

Sets path's fill rule.

##### Declaration

    public void SetWindingFill(bool winding_rule)

##### Parameters

Type | Name | Description
--- | --- | ---
bool | winding_rule | if winding_rule is true path will be filled using non-zero winding fill rule, otherwise even-odd fill will be used.

##### Exceptions

Type | Condition
--- | ---
PDFNetException | PDFNetException the PDFNet exception

#### UpdateTextMetrics()

Recompute the character positioning information (i.e. CharIterator-s) and text length.

Element objects caches text length and character positioning information. If the user modifies the text data or graphics state the cached information is not correct. UpdateTextMetrics() can be used to recalculate the correct positioning and length information.

##### Declaration

    public void UpdateTextMetrics()

##### Exceptions

Type | Condition
--- | ---
PDFNetException | PDFNetException the PDFNet exception