Foxit PDF SDK
foxit::pdf::ReflowPage Class Reference
Inheritance diagram for foxit::pdf::ReflowPage:
foxit::Base

Public Types

enum  Flags { e_Normal = 0x0, e_WithImage = 0x1, e_NoTruncate = 0x2 }
 Enumeration for parsing flags used for a reflow page. More...
 

Public Member Functions

 ReflowPage (const PDFPage &page)
 Constructor, from a parsed PDF page. More...
 
 ReflowPage (const ReflowPage &other)
 Constructor, with another reflow page object. More...
 
 ~ReflowPage ()
 Destructor.
 
float GetContentHeight () const
 Get content height after current reflow page object has been parsed. More...
 
float GetContentWidth () const
 Get content width after current reflow page object has been parsed. More...
 
Matrix GetDisplayMatrix (float offset_x, float offset_y, int width, int height, common::Rotation rotate) const
 Get the display matrix, according to the offset of top side between current reflow page and screen. More...
 
String GetFocusData (const Matrix &matrix, const PointF &point) const
 Get focus data corresponding to a given position in device coordinate system. More...
 
PointF GetFocusPosition (const Matrix &matrix, const char *focus_data) const
 Get the position in device coordinate system corresponding to a given focus data. More...
 
bool IsEmpty () const
 Check whether current object is empty or not. More...
 
bool IsParsed () const
 Check if current reflow page has been parsed or not. More...
 
bool operator!= (const ReflowPage &other) const
 Not equal operator. More...
 
ReflowPageoperator= (const ReflowPage &other)
 Assign operator. More...
 
bool operator== (const ReflowPage &other) const
 Equal operator. More...
 
void SetImageScale (float image_scale)
 Set image scale. This can be called before calling function ReflowPage::StartParse. More...
 
void SetLineSpace (float line_space)
 Set line space. This can be called before calling function ReflowPage::StartParse. More...
 
void SetParseFlags (uint32 flags)
 Set the parsing flag. This can be called before calling function ReflowPage::StartParse. More...
 
void SetScreenMargin (int left, int top, int right, int bottom)
 Set margin. This can be called before calling function ReflowPage::StartParse. More...
 
void SetScreenSize (float width, float height)
 Set screen size. This should be called before calling function ReflowPage::StartParse. More...
 
void SetTopSpace (float top_space)
 Set the top space. This can be called before calling function ReflowPage::StartParse. More...
 
void SetZoom (int zoom)
 Set zoom factor. This can be called before calling function ReflowPage::StartParse. More...
 
common::Progressive StartParse (common::PauseCallback *pause=0)
 Start to parse current reflow page. More...
 
- Public Member Functions inherited from foxit::Base
FS_HANDLE Handle () const
 Get the handle of current object. More...
 

Detailed Description

In order to display page contents in a small screen device, Foxit PDF SDK introduces the concept of "reflow page". In the reflow page, original PDF page contents will be laid out to fit the specified screen size.
For a PDF page, user may wants to keep focusing on a location in the reflow page when user switches between this PDF page and its related reflow page, or switch among these related reflow pages which are in different size. In order to track the focus location, Foxit PDF SDK uses "focus data" to represent the focus location. Focus data is similar to bookmark or destination in PDF, but it is simpler. User can store the focus data (or save the data to file) so that use can retrieved the focus location again by the focus data later, even if the size of reflow page is changed.
A reflow page object should be constructed from a parsed PDF page. This class offers functions to:

To render the reflow page, please use function common::Renderer::StartRenderReflowPage.

See also
PDFPage
common::Renderer

Member Enumeration Documentation

◆ Flags

Enumeration for parsing flags used for a reflow page.

Values of this enumeration can be used alone or in combination.

Enumerator
e_Normal 

Parsing flag for normal mode, without image.

e_WithImage 

Parsing flag for image mode.

e_NoTruncate 

Parsing flag to decide whether to allow to truncate the first/last image or line of text within the specified screen size or not.

The height of final parsed reflow page may be larger than the actual screen height. In this case, the content of a reflow page would be shown in more than one screen in application.
Application may use following modes to show such reflow page:

  • Show only part of content of the reflow page in the screen in one time. When user clicks or taps, show the previous or next part of content. This is like to turn to a page in a real book. Here, call this mode as "single screen mode".
  • Show the reflow page continuously – that means user can scroll the screen to see any part of content in this reflow page. Here, call this mode as "scroll screen mode".

If use "single screen mode" to show a reflow page, a truncate problem may occurs: the first line of text or image just shows the bottom half in the top of the screen, or the last line of text of image just shows the top half in the bottom of the screen. This flag can be set to avoid such problem.
If use "scroll screen mode", no need to use this flag.

Constructor & Destructor Documentation

◆ ReflowPage() [1/2]

foxit::pdf::ReflowPage::ReflowPage ( const PDFPage page)
explicit

Constructor, from a parsed PDF page.

Parameters
[in]pageA valid PDF page object which has been parsed.

◆ ReflowPage() [2/2]

foxit::pdf::ReflowPage::ReflowPage ( const ReflowPage other)

Constructor, with another reflow page object.

Parameters
[in]otherAnother reflow page object.

Member Function Documentation

◆ GetContentHeight()

float foxit::pdf::ReflowPage::GetContentHeight ( ) const

Get content height after current reflow page object has been parsed.

Returns
Content height.

◆ GetContentWidth()

float foxit::pdf::ReflowPage::GetContentWidth ( ) const

Get content width after current reflow page object has been parsed.

Returns
Content width.

◆ GetDisplayMatrix()

Matrix foxit::pdf::ReflowPage::GetDisplayMatrix ( float  offset_x,
float  offset_y,
int  width,
int  height,
common::Rotation  rotate 
) const

Get the display matrix, according to the offset of top side between current reflow page and screen.

This function can only be used when reflow page has been parsed.

Parameters
[in]offset_xOffset value, which means the offset from top side of current reflow page to the top side of screen.
[in]offset_yOffset value, which means the offset from left side of current reflow page to the left side of screen.
[in]widthWidth of the transformation area in screen, commonly in pixels.
[in]heightHeight of the transformation area in screen, commonly in pixels.
[in]rotateRotation value. Please refer to values starting from common::e_Rotation0 and this should be one of these values.
Returns
The display matrix.

◆ GetFocusData()

String foxit::pdf::ReflowPage::GetFocusData ( const Matrix matrix,
const PointF point 
) const

Get focus data corresponding to a given position in device coordinate system.

This function can only be used when reflow page has been parsed.
Focus data, similar to bookmark or destination in PDF, is used to locate the position of a specified content in reflow page. For a PDF page, position of a specified content is fixed and will not be changed even if the size of related reflow page is changed. So focus data can be used to locate the same content from a PDF page in its related reflow pages with different sizes but same reflow content.
Usually, user can call function ReflowPage::GetFocusData to get focus data for a specified location, and store the focus data. When the reflow page's size is changed, user can use the stored focus data in function ReflowPage::GetFocusPosition to get the new position and then still focus on or near the same content.

Parameters
[in]matrixA matrix returned by function ReflowPage::GetDisplayMatrix.
[in]pointThe point of a specified position, in device coordinate system.
Returns
The focus data.

◆ GetFocusPosition()

PointF foxit::pdf::ReflowPage::GetFocusPosition ( const Matrix matrix,
const char *  focus_data 
) const

Get the position in device coordinate system corresponding to a given focus data.

This function can only be used when reflow page has been parsed.
Focus data, similar to bookmark or destination in PDF, is used to locate the position of a specified content in reflow page. For a PDF page, position of a specified content is fixed and will not be changed even if the size of related reflow page is changed. So focus data can be used to locate the same content from a PDF page in its related reflow pages with different sizes but same reflow content.
Usually, user can call function ReflowPage::GetFocusData to get focus data for a specified location, and store the focus data. When the reflow page's size is changed, user can use the stored focus data in function ReflowPage::GetFocusPosition to get the new position and then still focus on or near the same content.

Parameters
[in]matrixA matrix returned by function ReflowPage::GetDisplayMatrix.
[in]focus_dataFocus data used to get its corresponding position in device coordinate system, with specified matrix. This is retrieved by previous calling of function ReflowPage::GetFocusData.
Returns
The position in device coordinate system.

◆ IsEmpty()

bool foxit::pdf::ReflowPage::IsEmpty ( ) const

Check whether current object is empty or not.

When the current object is empty, that means current object is useless.

Returns
true means current object is empty, while false means not.

◆ IsParsed()

bool foxit::pdf::ReflowPage::IsParsed ( ) const

Check if current reflow page has been parsed or not.

Returns
true means current reflow page has been parsed, while false means current page has not been parsed yet.

◆ operator!=()

bool foxit::pdf::ReflowPage::operator!= ( const ReflowPage other) const

Not equal operator.

Parameters
[in]otherAnother reflow page object. This function will check if current object is not equal to this one.
Returns
true means not equal, while false means equal.

◆ operator=()

ReflowPage& foxit::pdf::ReflowPage::operator= ( const ReflowPage other)

Assign operator.

Parameters
[in]otherAnother reflow page object, whose value would be assigned to current object.
Returns
Reference to current object itself.

◆ operator==()

bool foxit::pdf::ReflowPage::operator== ( const ReflowPage other) const

Equal operator.

Parameters
[in]otherAnother reflow page object. This function will check if current object is equal to this one.
Returns
true means equal, while false means not equal.

◆ SetImageScale()

void foxit::pdf::ReflowPage::SetImageScale ( float  image_scale)

Set image scale. This can be called before calling function ReflowPage::StartParse.

Parameters
[in]image_scaleThe image scale. This value should be positive number.
If no image scale is set, value 1.0f will be used by default.
Returns
None.

◆ SetLineSpace()

void foxit::pdf::ReflowPage::SetLineSpace ( float  line_space)

Set line space. This can be called before calling function ReflowPage::StartParse.

Parameters
[in]line_spaceThe line space. This value should between -25 to (height/2).
If no line space is set, value 0 will be used by default.
Returns
None.

◆ SetParseFlags()

void foxit::pdf::ReflowPage::SetParseFlags ( uint32  flags)

Set the parsing flag. This can be called before calling function ReflowPage::StartParse.

Parameters
[in]flagsParsing flags. Please refer to values starting from ReflowPage::e_Normal and this should be one or a combination of these values. If no parsing flag is set, value ReflowPage::e_Normal will be used by default.
Returns
None.

◆ SetScreenMargin()

void foxit::pdf::ReflowPage::SetScreenMargin ( int  left,
int  top,
int  right,
int  bottom 
)

Set margin. This can be called before calling function ReflowPage::StartParse.

If no margin has ever been set to current reflow page, Foxit PDF SDK will use value (0, 0, 0, 0) as default margin.
If new margin is set, the new margin will take effect until current reflow page has been re-parsed and rendered again.

Parameters
[in]leftThe left margin. This value should between 0 and (screen width / 3).
[in]topThe left margin. This value should between 0 and (screen height/ 3).
[in]rightThe left margin. This value should between 0 and (screen width / 3).
[in]bottomThe left margin. This value should between 0 and (screen height / 3).
Returns
None.

◆ SetScreenSize()

void foxit::pdf::ReflowPage::SetScreenSize ( float  width,
float  height 
)

Set screen size. This should be called before calling function ReflowPage::StartParse.

Before paring a reflow page, user should call this function to set the screen size for parsing the reflow page.

Parameters
[in]widthThe screen width.
[in]heightThe screen height.
Returns
None.

◆ SetTopSpace()

void foxit::pdf::ReflowPage::SetTopSpace ( float  top_space)

Set the top space. This can be called before calling function ReflowPage::StartParse.

This function is used to set the distance between the page's top and the screen's top. The distance will take effect when parsing a reflow page.

Parameters
[in]top_spaceThe top space. This value should between 0 and height.
If no top space is set, value 0 will be used by default.
Returns
None.

◆ SetZoom()

void foxit::pdf::ReflowPage::SetZoom ( int  zoom)

Set zoom factor. This can be called before calling function ReflowPage::StartParse.

If no zoom factor has ever been set to current reflow page, Foxit PDF SDK will use value 100 as default zoom factor, which means 100%.
If new zoom factor is set, the new zoom factor will take effect until current reflow page has been re-parsed and rendered again.

Parameters
[in]zoomZoom factor. The value represents the percent value, for example, 100 means 100%. This value should between 25 and 1000.
If no zoom factor is set, value 100 will be used by default.
Returns
None.

◆ StartParse()

common::Progressive foxit::pdf::ReflowPage::StartParse ( common::PauseCallback pause = 0)

Start to parse current reflow page.

It may take a long time to parsing a reflow page, so Foxit PDF SDK uses a progressive process to do this. All the resources about reflow page will be loaded after the reflow page is parsed.
This function should be called before any getting function of current reflow page object can be used.

Parameters
[in]pausePause callback object which decides if the parsing process needs to be paused. This can be NULL which means not to pause during the parsing process. If this is not NULL, it should be a valid pause object implemented by user. Default value: NULL.
Returns
A progressive object. Please check the rate of current progress by function common::Progressive::GetRateOfProgress. If the rate is not 100 yet, call function common::Progressive::Continue to coninue the progress until the progress is finished.