Re: is there an item.onTextStyleChanged ?

Author

Message

Daniel Zimmerman

Posted: 04/30/2004 0:28:32

Thanks for the ideas Sergey. We're working now with our own descendent

of the LabelItem, and it takes care of a lot of the workarounds we had

to do before.

We're running into a confusing situation, though, with regards to

streaming. In the method TRVLabelItemInfo.saveRVF, it first saves

header information, along with a hard-coded number of additional

properties, and then the additional properties.

What is the best way for us to plug into this system, and save our own

descendent's additional properties?

We would prefer to be able to call inherited TRVLabelItemInfo.saveRVF,

and not modify the code in that method. Is there a way to do this?

Thanks,

Daniel

"Sergey Tkachenko" <[email protected]> wrote in

news:[email protected]:

> Applying text style to text items and non-text items is performed in

> different ways.

> While RichViewEdit changes a style of text items directly, for

> non-text items it calls a special item method allowing them to respond

> on style applying.

> There is one more important difference between text and non-text

> items. For text item, style applying changes their style (StyleNo item

> property). For non-text item, item style must *not* be changed.

> StyleNo of non-text item is not an index in the collection of text

> styles, it's a constant identifying item type.

> May be it would be better to take the example from

> Demos\Addins\LabelItem\ as a base for your item. It may be not

> necessary to create a control - item can draw itself onto canvas and

> respond on mouse events. Even if you still need a control, you can

> look how LabelItem works with the associated text style.

> Note: there were some changes in the latest version of TRichView

> (available for registered users), so LabelItem was updated.

> Specifically, changes are related to style applying.

>> Hi Sergey,

>> What we are trying to do is this:

>> We are trying to embed a delphi control in trichview. This is

>> obviously easy. In our case, the control actually represents a

>> different, non-visual, aspect of our program to the user. Therefore

>> the control has text (representing the name and/or value of the

>> non-visual part). We are trying to keep the font of the text in the

>> control the same as what it should be. i.e. if the user selects

>> several items that includes the control, and changes the font on the

>> selection, the font on the control should change appropriately.

>> We have followed the example in the \demos\addins\chartItem to create

>> a new item. We have modified the print routine so our controlItem

>> prints properly. That works wonderfully.

>> When streaming out, we don't want to save the control (as happens in

>> default saveToRVF), because we want to keep the possibility of

>> changing the type of this control in future versions of our product.

>> We want to stream out the controlItem, without the control, and when

>> we stream the item back in, dynamically create the appropriate

>> control.

>> So, we now want to store the style number, so that when we stream in

>> our new item, we can reapply that style to the control. Now, I am

>> still relatively new to trichview, but it seems that the styleNum

>> property of an item is overloaded for different purposes. One is the

>> item type (i.e. text, component, bullet, table), and the other is a

>> font style number. It would be easier if these were two different

>> properties, so that a controlItem could have a font style, for

>> instance.

>> What is the easiest way to do what we need with trichview. We want to

>> be able to create a descendant of the control item and remember what

>> font style it had. I ordered your software but have not received the

>> source yet. Is there a setStyle for the controlItem I can override to

>> store the style number, even though it seems I have to make my style

>> return -12345 or something. How do I let richview know that this

>> style is being used by my item.

>> I know this is complex so I really thank you for your help in this

>> matter.

>> -Dave

>> Sergey Tkachenko wrote:

>> > Currently no function/event is called on changing text style of

>> > item. Can you explain why it's needed?

>> > May be I'll add this functionality.

>> >

>> > > I would like to execute some code when an item changes text

>> > > style. Is there a way to trap this? Preferably through an event,

>> > > but if need be we could override a setStyle-type method in our

>> > > own *ItemInfo descendent.