Accessing the current QTextBlock in QSyntaxHighlighter

[lorebett]

Hi

the documentation for

QSyntaxHighlighter::setCurrentBlockUserData ( QTextBlockUserData * data )
says

you can ask the current QTextBlock (retrieved using the QTextCursor::block() function) if it has a user data object set

but I don't understand how to actually retrieve the current QTextBlock, since on what should I call QTextCursor::block()?

thanks in advance
Lorenzo

[wysota]

The text cursor is usually positioned somewhere in the text of QTextDocument. You can move it anywhere you want and you can query for the block it is in.

[lorebett]

The text cursor is usually positioned somewhere in the text of QTextDocument. You can move it anywhere you want and you can query for the block it is in.

OK, so if I have the position of the cursor I can get the block the cursor is in, but the problem is now: how can I get the current cursor position?

[wysota]

I take it that you want to do something with the highlighter... in that case use QSyntaxHighlighter::currentBlockUserData() and forget about the cursor.

[lorebett]

I take it that you want to do something with the highlighter... in that case use QSyntaxHighlighter::currentBlockUserData() and forget about the cursor.

I don't think that's enough: I need to access the user data of the previous block, because int previousBlockState () const is not enough... and to access the previous block user data I need to access the current block, and through the current block I can get access to the previous block by using QTextBlock::previous()...

[wysota]

Could you say why you need to access the previous block?

[lorebett]

Could you say why you need to access the previous block?

I'm trying to implement syntax highlighting through GNU Source-highlight and, in case I enter in a specific highlight state (say, e.g., comment state) I need to store such information in the current block's user data (and I can do this now), but I also need to inspect the previous block user data (to know whether we're inside a specific highlight state).

I don't see any way to access this since, also using TextEdit->cursor()->block() is not enough, since when QSyntaxHighlighter decides that many blocks need to be highlighted TextEdit->cursor()->block() only returns the block where the cursor is, and this is obviously not enough.

By the way, previousBlockState() is not enough for me, since I need to set specific user data

[wysota]

According to me all you need is the state of the previous block. When you highlight the previous block, you mark its state as "in comment" and then when the next block is being highlighted, you read that value and you know you're still in a comment. What extra data would you like to store, specifically?

[lorebett]

According to me all you need is the state of the previous block. When you highlight the previous block, you mark its state as "in comment" and then when the next block is being highlighted, you read that value and you know you're still in a comment. What extra data would you like to store, specifically?

I need to store also the stack information: GNU Source-highlight is powerful enough to handle nested highlighting states, using stacks, and only the (integer) state of the previous block is not enough

[wysota]

If it's only a "state" then that's enough. You can use each bit of the integer to mark a state, therefore you can mark a hierarchy of 32 states - for instance "1" means the paragraph is in state "1" and 9 marks it is in states "1" and "4". I doubt you'll ever have more stacks deeper than 32 levels.

If you can't live with that, simply create a structure which you will index by an integer ("state") that will return the real state associated with a given index.

[lorebett]

If it's only a "state" then that's enough. You can use each bit of the integer to mark a state, therefore you can mark a hierarchy of 32 states - for instance "1" means the paragraph is in state "1" and 9 marks it is in states "1" and "4". I doubt you'll ever have more stacks deeper than 32 levels.

If you can't live with that, simply create a structure which you will index by an integer ("state") that will return the real state associated with a given index.

No, I need actual objects: the stack contains references to state objects, so I need to store user data...

probably the idea of the structure might help