Display screen capable of being subjected to a scroll procedure

• US 20070146377A1
• Filed: 10/13/2003
• Published: 06/28/2007
• Est. Priority Date: 10/16/2002
• Status: Active Grant

• Current Assignee: Thomson Licensing SA (Vantiva SA)
• Original Assignee: Thomson Licensing SA (Vantiva SA)
• Inventors: Villers, Jean-Stephane
• Granted Patent: US 7,796,142 B2
• Time in Patent Office: Days
• US Class Current: 345/573
• CPC Class Codes: G09G 5/346 for systems having a bit-mapped display memory

Abstract

The invention concerns a method for displaying a document on a display screen capable of being subjected to a scroll procedure, involving the following steps: providing the document with an amount of graphic memory to create a buffer memory of the visible part of the document and zones nearest to said visible part; calculating and cutting out into pixmaps said memory; relatively positioning said pixmaps with respect to the entire document and its visible part; filling up the content of the pixmaps, when the document is subjected to a display or scroll procedure, recopying the pixmap content in the display window; and repeating the relative positioning of the pixmaps with respect to the document.

Claims

1. A method of displaying a document on a display screen capable of being subjected to a scroll procedure, comprising the following steps:

a step of allocating the document a quantity of graphics memory so as to create a buffer memory of the visible part of the document and of the zones closest to this visible part and referred to as anticipation bands,

a step of calculating and of chopping of this memory into pixmaps as a function of the size of the document, of the visible part, and of those of the anticipation bands,

a step of relative positioning of these pixmaps with respect to the complete document and its visible part,

a step, that can be carried out as a background task, of filling the content of the pixmaps with a priority system dependent on the proximity of the pixmap with respect to the visible zone,

when the document is subjected to a display procedure or to a scrolling, a step of copying the content of the pixmaps into the display window with previously if necessary a step forcing the updating of the pixmaps involved in the display if the previous step has not terminated same,

and return to the step of relative positioning of the pixmaps with respect to the documents as a function of the new position of the visible part.

2. The method as claimed in claim 1, wherein the anticipation bands comprise a minimum of one column of pixmaps on the right and on the left of the visible window as well as a row of pixmaps at the bottom and at the top, except in the case where the visible window approaches the edge of the document.

3. The method as claimed in claim 1, wherein the pixmaps are chopped into rectangles which are drawn successively with each call of a background task.

4. The method as claimed in claim 3, wherein the background task also has the function of constructing the anticipation bands.

5. The method as claimed in claim 3, wherein, each call of this background task, comprises:

reorganization of the pixmaps if a scroll has been performed,

if no repositioning of the pixmaps has occurred, drawing of the first rectangle of a pixmap determined as a function of a criterion of distance away from the visible zone of the document.

6. The method as claimed in claim 1, which uses a synchronization mechanism allowing the possible forcing of the data to be displayed into the pixmaps.

7. The method as claimed in claim 1, wherein an immediate drawing is carried out in two cases:

when an “

expose”

event compels the drawing of a part of the display window though this part has not yet been drawn in the anticipation bands,

or when an element of the document is modified graphically in the display window.

8. The method as claimed in claim 1, wherein the document is a HyperText Markup Language (HTML) document.

9. A digital television decoder for displaying a document on a display screen capable of being subjected to a scroll procedure, configured to:

allocate the document a quantity of graphics memory so as to create a buffer memory of the visible part of the document and of the zones closest to this visible part and referred to as anticipation bands,

calculate and chop this memory into pixmaps as a function of the size of the document, of the visible part, and of those of the anticipation bands,

relatively position these pixmaps with respect to the complete document and its visible part,

fill the content of the pixmaps with a priority system dependent on the proximity of the pixmap with respect to the visible zone, wherein filling the content of the pixmaps can be carried out as a background task,

when the document is subjected to a display procedure or to a scrolling, copy the content of the pixmaps into the display window, and previously, if necessary, force the updating of the pixmaps involved in the display if the previous step has not terminated same,

and relatively position the pixmaps with respect to the documents as a function of the new position of the visible part.

10. The digital television decoder as claimed in claim 9, wherein the anticipation bands comprise a minimum of one column of pixmaps on the right and on the left of the visible window as well as a row of pixmaps at the bottom and at the top, except in the case where the visible window approaches the edge of the document.

11. The digital television decoder as claimed in claim 9, wherein the pixmaps are chopped into rectangles which are drawn successively with each call of a background task.

12. The digital television decoder as claimed in claim 11, wherein the background task also has the function of constructing the anticipation bands.

13. The digital television decoder as claimed in claim 11, wherein each call of the background task, comprises:

reorganization of the pixmaps if a scroll has been performed, and

if no repositioning of the pixmaps ha occurred, drawing of the first rectangle of a pixmap determined as a function of a criterion of distance away from the visible zone of the document

14. The digital television decoder as claimed in claim 9, wherein a synchronization mechanism is used to allow the possible forcing of the data to be displayed into the pixmaps

15. The digital television decoder as claimed in claim 9, wherein an immediate drawing is carried out in two cases:

when an “

expose”

event compels the drawing of a part of the display window though this part has not yet been drawn in the anticipation bands,

or when an element of the document is modified graphically in the display window.

16. The digital television decoder as claimed in claim 9, wherein the document is a HyperText Markup Language (HTML) document.