I have a single line CEikLabel in my application that needs to scroll text.
The simple solution that comes to mind (but possibly naive) would be something like..
[begin pseduo code]
on timer.fire {
set slightly shifted text in label
redraw label
}
start timer
[end pseudo code]
Using a CPeriodic class as the timer and label.DrawDeferred() on each update.
Do you think this is the best way, it may be rather inefficient redrawing the label two or three times a second.. but is there any other way?
Thanks :)
I've seen the timer based solution used for scrolling item names in listboxes.
A couple of things to watch out for are that it could flicker a bit while scrolling and that you need to make sure the text you put on the label is not too long, otherwise it will automatically clip the string and add an elipsis (...)
Use TextUtils::ClipToFit to get a string that fits on the label and remove the elipsis it adds before putting the text on the label (search for KTextUtilClipEndChar in your clipped string). You will need to work out how many characters to skip at the beginning of the string before passing it to the clip function.
I don't know whether there is another way to do it and can't say whether the approach you have in your mind will be inefficient. However, you may want to take a look at this thread which discusses pretty much the same question as yours and also briefly mentions somewhat the same solution as the one you have conceived of.
I have done it like this
TTimeIntervalMicroSeconds32 scrolltime(70000);
iPeriodicScroll = CPeriodic::NewL(CActive::EPriorityIdle);
iPeriodicScroll->Start(scrolltime, scrolltime, TCallBack(CVisTagContainerView::ScrollTextL, this));
and then in the repeated function
CEikLabel *label = iContainer->Label();
const TDesC16 *temp = label->Text();
if (temp->Length() <= 0) {
if (iTextState != ETextIdle) { return; }
DownloadMoreTextL();
return;
}
TPtrC16 right = temp->Right(temp->Length()-1);
label->SetTextL(right);
label->DrawDeferred();
So text moves right to left, and when all gone, the label is repopulated by DownloadMoreTextL
Related
is it possible to react when the mouse is over a word ? Suppose I want to show a bubble with a description of the thing I'm currently hovering. Seems strangely difficult to do.
I think it is possible but might be a little hard.
You have the MouseHover event however you don't know what word you hovered so it might be a little hard.
You can get the mouse localization with this:
Point mouseLocation = new Point(e.X, e.Y)
Then if you use a fixed-width type font you know the size of each line/character then you can calculate it.
Some code that helps with position/line transition:
var line = scintilla.LineFromPosition(startPos);
startPos = scintilla.Lines[line].Position;
scintilla -> Control Name
For a better view try seeing this:
https://github.com/jacobslusser/ScintillaNET/wiki/Custom-Syntax-Highlighting
https://github.com/jacobslusser/ScintillaNET/wiki/Basic-Text-Retrieval-and-Modification
Edit:
Not really a good answer soo 2nd try
[scintilla name].CurrentPosition -> you can get the word you selected if I'm not mistaken but I don't know if you can do it by hovering.
Then do the interpretation of the word and it might work.
Try reading this:
https://github.com/jacobslusser/ScintillaNET/issues/149
3rt Try.
Let's hope it's the best one.
https://github.com/Ahmad45123/AutoCompleteMenu-ScintillaNET
There is AutoCompleteMenu for Scintilla that has a hover property.
I'm not sure how it works but might be what you're searching for.
I'm trying to implement a syntax-coloring text editor that also does things like insert whitespace at the start of a new line for you, or replace text with text attachments.
After perusing the docs again after a previous implementation had issues with undoing, it seems like the recommended bottleneck for this is NSTextStorageDelegate's textStorage(_,willProcessEditing:,range:,changeInLength:) method (which states that Delegates can change the characters or attributes., whereas didProcessEditing says I can only change attributes). This works fine, except that whenever I actually change attributes or text, the text insertion mark moves to the end of whatever range of text I modify (so if I change the style of the entire line, the cursor goes at the end of the line).
Does anybody know what additional call(s) I am missing that tell NSTextStorage/NSTextView not to screw up the insertion mark? Also, once I insert text, I might have to tell it to move the insertion mark to account for text I've inserted.
Note: I've seen Modifying NSTextStorage causes insertion point to move to the end of the line, but that assumes I'm subclassing NSTextStorage, so I can't use the solution there (and would rather not subclass NSTextStorage, as it's a semi-abstract subclass and I'd lose certain behaviours of Apple's class if I subclassed it).
I found out the source of the problem.
And the only solution that will work robustly based on reasons inherent to the Cocoa framework instead of mere work-arounds. (Note there's probably at least one other, metastable approach based on a ton of quick-fixes that produces a similar result, but as metastable alternatives go, that'll be very fragile and require a ton of effort to maintain.)
TL;DR Problem: NSTextStorage collects edited calls and combines the ranges, starting with the user-edited change (e.g. the insertion), then adding all ranges from addAttributes(_:range:) calls during highlighting.
TL;DR Solution: Perform highlighting from textDidChange(_:) exclusively.
Details
This only applies to a single processEditing() run, both in NSTextStorage subclasses and in NSTextStorageDelegate callbacks.
The only safe way to perform highlighting I found is to hook into NSText.didChangeNotification or implement NSTextDelegate.textDidChange(_:).
As per #Willeke's comments to the OP's question, this is the best place to perform changes after the layout pass. But as opposed to the comment thread, setting back NSText.selectedRange does not suffice. You won't notice the problem of post-fixing the selection after the caret has moved away until
you highlight whole blocks of text,
spanning multiple lines, and
exceeding the visible (NSClipView) boundaries of the scroll view.
In this rare case, most keystrokes will make the scroll view jiggle or bounce around. But there's no additional quick-fix against this. I tried. Neither preventing sending the scroll commands from private API in NSLayoutManager nor avoiding scrolling by overriding all methods with "scroll" in them from a NSTextView subclass works well. You can stop scrolling to the insertion point altogether, sure, but no such luck getting a solid algorithm out that does not scroll only when you perform highlighting.
The didChangeNotification approach does work reliably in all situations I and my app's testers were able to come up with (including a crash situation as weird as scrolling the text and then, during the animation, replacing the string with something shorter -- yeah, try to figure that kind of stuff out from crash logs that report invalid glyph generation ...).
This approach works because it does 2 glyph generation passes:
One pass for the edited range, in the case of typing for every key stroke with a NSRange of length 1, sending the edited notification with both [.editedCharacters, .editedAttributes], the former being responsible for moving the caret;
another pass for whatever range is affected by syntax highlighting, sending the edited notification with [.editedAttributes] only, thus not affecting the caret's position at all.
Even more details
In case you want to know more about the source of the problem, I put more my research, different approaches, and details of the solution in a much longer blog post for reference. This here, though, is the solution itself. http://christiantietze.de/posts/2017/11/syntax-highlight-nstextstorage-insertion-point-change/
The above accepted answer with the notification center worked for me, but I had to include one more thing when editing text. (Which may be different from selection).
The editedRange of the NSTextStorage was whack after the notification center callback. So I keep track of the last known value myself by overriding the processEditing function and using that value later when I get the callback.
override func processEditing() {
// Hack.. the editedRange property when reading from the notification center callback is weird
lastEditedRange = editedRange
super.processEditing()
}
I have a flash game where I have a picture designed to be the textbox for a prompt and textbox inside with the relevant text but the textbox is being hidden by the image. Anyone know how to make is so that the textbox is guaranteed to be on top or whatever I need to do to keep this from happening?
The other answer using setChildIndex will definitely work, however, I think a different design approach is really what you should be doing to remove the headache altogether.
For example in a game I might have different layers such as :
backgroundLayer
gameLayer
interfaceLayer
Those 3 Sprite layers would get added to the stage in that order. I would then add display objects to the appropriate layers. So anything I added to the backgroundLayer or gameLayer would ALWAYS be 'behind' my user interface on the interfaceLayer.
That allows you to not have to worry about the layering constantly. The answer with setChildIndex will fix the problem for that moment, but should something else be added to the container it will overlap your textbox, which is something I don't assume you want.
here's an example :
var backgroundLayer:Sprite = new Sprite;
var gameLayer:Sprite = new Sprite;
var interfaceLayer:Sprite = new Sprite;
addChild(backgroundLayer);
addChild(gameLayer);
addChild(interfaceLayer);
now, whatever you add to interfaceLayer, will ALWAYS be on top of objects you add to gameLayer or backgroundLayer.
So in the case of your text box, just add it to your interfaceLayer and any other objects you want behind it, you add to the gameLayer or backgroundLayer.
The order of adding display objects to display object containers effect their z-order, in other words the front to back order. The last added display object becomes the frontmost. So the child index of the children of a display object container is important for drawing of overlapped children.
If you put picture and text on the same DisplayObjectContainer such as a MovieClip:
Lets say your DisplayObjectContainer is mc.
And your textbox is txt
Please try this:
mc.setChildIndex(txt, mc.numChildren-1);
I want to persist the user's location in the document he or she is browsing, then bring them back to that spot when they return from tombstoning or between sessions.
My first approach was to wrap the browser component in a scrollviewer, but it turns out it handles its own scrolling and the scrollviewer never changes its verticaloffset.
My guess is that the browser component must have a scrollviewer or something like it embedded in it. I need to get the verticaloffset and scroll to an offset.
Any guesses how to get there?
My next approach would be a painful mish-mash of javascript and c# to figure out where they are...
Because of the way the WebBrowser control is built you'll need to track scrolling in Javascript then pass the location to managed code to handle storage of that value.
On resuming you'll need to have the managed code pass the scroll position to a Javascript function to reset the scroll position.
That's the theory but I haven't looked at the funcitonality around javascript scrolling events in the WebBrowser yet. That's the only place I can see possible problems.
Would be good to hear how you get on.
I've accepted Matt's answer, but I want to put in some details here. I'm also going to blog about how I did it once I'm completely done.
Since the WebBrowser component is essentially a black-box, you don't have as much control as I would like. Having said that, it is possible to get and set the vertical offset.
Javascript lets you ask for the value, but different browsers use different variations on HOW to ask. For THIS case I only have one browser to worry about.
First I make a couple of simple javascript functions:
function getVerticalOffset() {
return document.body.scrollTop;
}
function setVerticalOffset(offset) {
document.body.scrollTop = offset;
}
Next I call into the WebBrowser using the InvokeScript method on the browser object.
I'll post an update here with a link to my blog when I get the full write-up done.
I have been writing an eBook reader and had a similar question. Code for setting a scroll position has been easy enough to find.
Code for setting vertical scroll position:
string script = string.Format("window.scrollBy(0,{0});", "put your numeric value here");
wb_view.InvokeScript("eval", script);
Google didn't help much in finding solution for getting the value of current scroll position. Lacking any knowledge in javascript it took me almost two hours to get it right.
Code for getting the vertical scroll position:
var vScroll = wb_view.InvokeScript("eval",
"var vscroll = window.pageYOffset; vscroll.toString();");
When using custom-draw (NM_CUSTOMDRAW) to draw the entire contents of a ListView SubItem (in Report/Details view), it would be nice to be able to apply the same left and right
padding in my custom paint method that is applied by the control itself for non-custom-drawn items.
Is there a way to programmatically retrieve this padding value? Is it
related to the width of a particular character (" " or "w" or something?) or
is it a fixed value (6px on left and 3px on right or something) or...?
EDIT: To clarify, I want to add the same padding to my NM_CUSTOMDRAWn SubItems that the control adds to items that it draws, and the metric that I'm looking for, for example, is the white space between the beginning of the 2nd column and the word "Siamese" in the following screenshot (Note: screenshot from MSDN added to help explain my question):
(source: microsoft.com)
Note that the word "Siamese" is aligned with the header item ("Breed"). I would like to be able to guarantee the same alignment for custom-drawn items.
use ListView Header message HDM_GETBITMAPMARGIN
see link text
ListView_GetSubItemRect (LVM_GETSUBITEMTECT)
http://msdn.microsoft.com/en-us/library/ms930172.aspx
Despite what the documentation says I suspect LVIR_LABEL returns just the returns the bounding rectangle of the item text, as per ListView_GetItemRect.
(This just kept niggling me as I though I had actually seen an answer somewhere when playing with NM_CUSTOMDRAW).
Edit After Comment 2:
I imagine you have seen NMLVCUSTOMDRAW which if you are willing to use Version 6.0. has rcText. I wouldn't since I use Win2K.
Given what you have found I would go back to the suggestion of using
ListView_GetItemRect to get LVIR_LABEL and compare that with LVIR_BOUNDS and use the difference.
the way for doing this is retrieving the format of the corresponding column with
ListView_GetColumn()
then check the retrieved myLVCOLUMN.mask
LVCOLUMN myLVCOLUMN;
myLVCOLUMN.mask=LVCF_FMT;
ListView_GetColumn(hwnd,nCol,&myLVCOLUMN);
then when we draw the corresponding label belonging to that column
if(myLVCOLUMN.fmt & LVCFMT_CENTER)
DrawText(x,x,x,x, DT_CENTER | DT_WORD_ELLIPSIS );
else if (myLVCOLUMN.fmt & LVCFMT_RIGHT)
DrawText(x,x,x,x, DT_RIGHT | DT_WORD_ELLIPSIS );
else
DrawText(x,x,x,x, DT_LEFT | DT_WORD_ELLIPSIS );
I would assume that GetSystemMetrics() is that you need to look at. I think that SM_CXEDGE and SM_CYEDGE are probably the values you want, but don't quote me on that. ;-)
Can only guess without seeing your output.
A few suggestions: If you are using the DrawTextEx function, have you have experimented with DT_INTERNAL et al?
Are you accidentally putting in a blank image/icon.
Does it look ok in classic screen mode? If so I would look at XP Theme functions to see if some thing is going on.
Late edit after first comment:
I wonder if the size of rectangle matches the space required for the LVN_ENDLABELEDIT edit box around the text so the text doesn't move (or for a focus rectangle)?
I guess you could compare the result of LVM_GETITEMRECT with LVIR_LABEL on the first column and use the difference as your left border.