I have a TListBox that can have a very long stringlist when loaded so I have the operator initiate a Sort by clicking a button. Sometimes the sort can take close to a minute and the operator is left wondering what's happening.
Is there any way I can use a TProgressBar to show that something is happening? If so, how?
OR
Can I Grey (visually disabled) the screen at the start and then color back to white when the sort is completed? If so, how?
Thanks
I believe that your fundamental problem is that you are using a visual control as a container. Sorting the list inside the container will have terrible performance. Put 60,000 strings in a TStringList and you'll be able to sort them instantly.
Rather than holding the items in the visual control, you can operate it in virtual mode. That will be the most efficient way to operate.
If you make these changes then you won't need a progress bar.
Related
I've occasionally come across examples of edit controls that have a special indicator to assist the user, like so:
and I'd like to be able to implement similar in my own code.
The screen-scrap is actually from the property editor for the TIBQuery Sql property and isn't quite what I'm after (otherwise I'd just look in the IBX code) because it disappears as soon as the user types anything. There are others where the indicator moves so as to keep its place as the user types something, but doesn't replace the caret, otherwise I'd just do that.
So my question is, how to implement a special indicator of the type I've tried to describe, that can be positioned and turned on/off in code? The simplest thing I could think of would be to somehow temporarily add a special glyph to the edit control's character set, but I have no idea how to do that, nor how to colour it differently than the control's text content.
I want the first node to stay on top and should not be affected during scroll. The first node will be like a column header(stays on top even scrolling). How can I do that?
This kind of behavior is something you can currently find in spreasheets:
Lock first column (Header.Columns[0].Options → coFixed)
Lock first row (?)
I'm trying to insert a picture for more explanation but I don't have 10 reputations. Sorry about that. Thanks in advance.
You can't as VirtualTree doesn't support such a behaviour. Besides, VT already has header support (include hoVisible to Header.Options to show it) why don't you use that? You can custom paint it (see OnHeaderDraw events) if you want it to look like ordinary node.
I have this tool tip that is created every so often. What is the appropriate actionscript etiquite?
A. To Create and remove the tooltip moveclip when needed?
or
B. To hide and show the tooltip movieclip when needed?
With these A and B, the answer is B, because creating and then removing an object a lot of times creates a lot of garbage in the memory, which eventually leads to garbage collector calls, that slow your SWF's performance. You can easily go with a single tooltip MC, just fill it with information that corresponds to the new mouse coordinates before you show it.
There is another question, not so straightforward as yours, about how to hide and show a movie clip, either via visible property or via addChild() and removeChild() (AS3 only). If you are using AS2 or AS1, use visible property to hide and show your tooltip.
There are three ways to hide something in Actionscript : Alpha, visible and remove child.
Apha: If you turn the alpha zero the renderer always comes to this displayObject and renders it at alpha zero. So the object is always rendered you just cannot see it.
Visible == false In this case the object still exists in your displaylist. So the renderer comes to the object. Sees it's property is false and leaves it but it still exists in the display list.
removeChild This means that you're removing the object from the display list. This means that the renderer never had to even check for it. Which makes it the fastest option.
addChild doesn't take that much computing power as visible check. I'm sure you can find benchmarks on this.
If you don't have a lot of objects on yours screen and the tooltip is there every second I'd go with visible is false. In all other cases go with the third option.
On a side note, I've found it always easier to manage them with a toolTipManager. A class that makes sure that you have one tooltip on the screen because usually users only use one tooltip. So that makes things easier for me. I just always create the necessary tooltips and add them to the displaylist when required and remove them. (Not recreate them) At the same time have only one tooltip on stage.
Sure I've seen this done before but off-hand I can't find any examples.
I've got a TListView, set in 'report' viewstyle. It has about half a dozen subitems, and one thing we'd like to do is have the 'hint' (tooltip) on the listview dynamically show another field of data. That is, each time you move the mouse over any given row, the 'hint' would show some text relevant to that particular row.
I'm partway there - I can do this using the OnInfoTip method, but unfortunately once a tip has appeared, Windows seems to decide that I don't need to see a hint for the listview again until I move the mouse away from the listview and then back 'over' it again. Simply moving the mouse down to the next row, all-the-time keeping the mouse over the control, doesn't persuade the program to display the new hint.
Just to be clear - I've got OnInfoTip working so that the program does display the right hint relevant to the item I first moved the mouse over. Changing the hint text isn't the issue. The problem is that moving the mouse to another item in the listview doesn't cause the software to show a new hint. (Hope that makes sense).
Is there some proper way of getting this behaviour to work, or am I going to end up doing something icky with mouseovers and then manually drawing a hintbox (etc)?
check the following link:
Display Custom Hints for TListView Sub Items
Edit:
I just checked it now on delphi7 it's showing the hint for every row dynamically after moving the mouse on the listview.
Offtopic: This is simple in Virtual Treeview component, it is build-in feature.
i was using the OnInfoTip event (i didn't need hints for the subitems). the hint was "flashing" (show/hide/show/hide/show/hide/show/hide). found the listview's ShowHint was false. set it to True and it worked as it should.
I have created some custom controls (TCustomControl) in Delphi that I can move them at runtime but only one by one. How I can select two or more of these controls, at runtime again, and move them around all together with the mouse?
Thank you.
Another comercial solution would be from DevExpress: LayoutControl. It allows for drag and drop, grouping, full rearrange, hiding and adding of components at runtime.
If you can't find any simpler way, you can always do it manually. Keep a list of all the selected controls. When the drag operation begins, make another list, this one containing TPoint values indicating how far on both axes each control's Top and Left properties are from the mouse's position. Then, as the user drags the control, continually update the selected controls to keep them at the proper relative positions to the mouse pointer.
I once used a component named handles, that if I remember correctly wasn't too difficult to update to the later versions of Delphi and supported multi-select.
How about a commercial solution? The screen shot shows alignment tools, which would suggest that it supports multi-select.