I have a project that I'm working on that has a TreeView Control in it. For everything underneath Level 1, those nodes are being used as a bookmark function, so we want a Tri-State CheckBox there. I found a control that I'm using here.
However, as the top two levels in the TreeView do not need bookmarking, the customer wants an Image there. I found this page who's response gets CheckBoxes to disappear on specific Nodes. Unfortunately, the API calls clash with the ones used in the above Tri-State TreeView and they both can't work at the same time.
Basically, what I'm looking for is how to get Images in nodes on the top two levels, and Tri-State CheckBoxes on the lower levels. I'd be more than willing to try another Tri-State CheckBox if necessary.
Also, when the user clicks on the Image in the top two levels, the image shouldn't change. I found this page which does keep the image from changing, but removes the PlusMinus, Lines, and RootLines from the control.
Sorry in advance that this is such a ridiculous and specific request.
Ok, I finally got this figured out. Using the Tri-State Treeview Control, I am able to still have access to the AfterClick event on the Treeview.
I had added a series of Checkbox icons to the ImageList, and after determining which CheckState (of the 3) my underlying object was in. Then I set the ImageIndex, SelectedImageIndex, and StateImageIndex (probably don't need the last one, but I was being thorough) to the proper index of the ImageList.
I won't post any code for now, but if you are trying to do the same thing, let me know and I'll upload until it becomes clear.
Related
I need to implement a threaded view of sorts in an old VB6 app. It should look similar to this:
So, it's like a TreeView of sorts but there are buttons on the right (for each row) that could be pressed. The view does not need to collapse - it always stays in the expanded mode. The users should be able to respond to each node (via the comment button on the far right). And, of course, users should be able to scroll through the entries.
What are some of the ways I could implement this? I am open to 3rd party controls, paid or not.
VSFlexGrid has an outline mode. You can set the indent per row via the RowOutlineLevel property. It supports word wrap, images, etc within its cells/columns so you should be able to get pretty close to what you want. It also supports owner-drawn which lets you fully customize the cell painting (for example, to get those rounded corners).
I'm sure there are other controls out there as well...
I'm writing a diagram editor in Qt with Graphics View Framework.
Currently I'm just trying to create a simple Node (QGraphicsItem) on GraphScene (QGraphicsScene). I created a Canvas (QGraphicsView) and added a grid to it. I can even add Nodes and move them around on scene. My final goal is to have different working modes, editing and styling options, etc. For now I just want to know how can I setup selection for Nodes already present on scene. I tried doing it with mouse events but noticed that event calls for selection and Node insertion overlap... When I try to select something a new Node is created... This is my first Qt application so I don't fully understand how the functionality I want to achieve should be designed.
How the Selection Rectangle should be properly drawn?
How should I manage mouse events that conflict with each other?
You can use a checkable button/action(that's a QPushButton/QAction with a checkable property set to 'true) to switch between Edit & Insert mode. Then you check the state in your mouse event and insert a new item only if you're in Insertion mode.
You can also distinct between mouse buttons - insert item when dragged with the right button for example
Or use QKeyboardModifiers - for example: on drag + Ctrl - insert item.
Hope this helps.
In case of the overlapping mouse events, you should have a single place (like QGraphicsView to handle the mouse clicking/moving events) and create a state machine and then handle the events according to the state you are in. You need to plan your architecture well and that can be really complex task.
set your state enum/constants
refer to the current machine state in your events in your if conditions
keep your "business logic" on a single place
Like it's shown in these two NodeEditor tutorials #11 and #12: https://www.youtube.com/watch?v=pk4v2xuXlm4 and https://www.youtube.com/watch?v=-VYcQojkloE)
If you still want more in depth explanation of the functionality and events of Qt, here is a full list of tutorials with implementing all possible features like dragging edges to nodes, selecting them and deleting them, cutting edges, serialization, etc., you can have a look on the whole list of 50 tutorials I've recorded here: https://www.blenderfreak.com/tutorials/node-editor-tutorial-series/.
I'm putting a link to the whole list, since it's not possible to write all the code on this page...
What would be the appropriate way for selecting a particular row in a paginated view.
For example, while trying to select a particular row in Yahoo Inbox you can use the pointer to select the check box and if you try to click beyond the check box, no action is taken.
But while trying to select a particular row in GMail Inbox you can use the pointer to select it or if you navigate away from the checkbox it changes into a thumbnail but allows you to select the row.
Which method is preferable from a usability perspective and how to implement the thumbnail based selection as done by GMail
Both methods are appropriate, and both can be very usable.
I think the main difference is that row selection (the system used by Gmail) is more like a desktop application and a little less web-like. With links (like in the Yahoo inbox or StackOverflow), it's completely obvious that you're supposed to click on them. With rows, you sort of have to figure that out that you can click them, but I doubt it takes people long.
One thing to keep in mind is that, if you go with row selection, it's probably a good idea to bunch together any other clickable control (like checkboxes, links, or "favorite" stars). This way, you can click anywhere on the row. If you intersperse controls along the row, you increase the likelihood users will make clicking errors (aiming for the row but accidentally clicking some other control), and it will make it harder for users to recognize that the row itself is a clickable region.
So, both are perfectly acceptable user interfaces. You'll have to decide which one is a better match for your particular situation. I think, in general, links are a little bit more versatile, but with clickable rows, you know you can click anywhere and it will work.
I am using the Win32 API and MS Visual C++ 6 to build a tree view of a directory structure, with check boxes associated with each tree view item. My goal is to be able to check a parent folder, and have that automatically check all of its associated children.
However, after digging through MSDN, I have not been able to find a control notification message for an item being checked, only when an item is selected. I have considered using a selection notification message to prompt the program to poll the item and see if its current 'check state' is true, but I am not sure that checked and selected can be tied together in such a way, and am also concerned about the overhead associated with constantly polling items as a user moves through a very large directory.
Has anyone had experience setting up this scenario? Are my concerns about the overhead of polling a GUI element justified?
There isn't any notification. You can write your own, though. Just handle mouse click and use hittest to see if the mouse cursor is on the state image. For completeness handle the space key and send the same notification for the selected item too.
As of Windows Vista, Microsoft has introduced NM_TVSTATEIMAGECHANGING and a corresponding NMTVSTATEIMAGECHANGING structure. I'm not sure why this is not documented with the Tree View notifications but instead in the General Control Reference section.
This notification code is sent by the tree control when the state image is changing (i.e. when the check box is clicked).
The NMTVSTATEIMAGECHANGING struct has a iOldStateImageIndex and iNewStateImageIndex field that specifies the corresponding change. This information can be used to determine the new state image that will be displayed (1 is the unchecked box and 2 is the checked box)
Vista also introduces dimmed, partial and excluded checks though at the moment I'm not sure how those are represented by the state image index as the two base cases above.
Here is the best way by MSDN (TreeView::AfterCheck Event):
http://msdn.microsoft.com/en-us/library/system.windows.forms.treeview.aftercheck(v=vs.110).aspx
It's a longshot that anyone can help with this, but here goes. I inherited a VB6 app with a Janus GridEX control. It iterates through records, and is editable. Problem is, if I edit a cell and hit the button to go to the next record, the change is applied to the next record, not the one I was editing. It's like, I need it to finish up the edit before going to the next record. I've had this sort of problem before in VC++, and sometimes you have to "KillFocus" on the control you're on or something. I just don't know what to do here. I tried sending a carriage return, since if you return out of the edit cell, it works, but sending a carriage return manually doesn't work. What's the secret?
Is your grid bound or unbound?
It's hard to tell from your description, but I imagine that if your are having this problem then it's probably bound.
As the other answer asked, is the button the RecordNavigator that is built into the control or is it a separate button? The reason I bring this up again, is that I have seen issues in the VB6 applications I support where a toolbar will often intercept and interfere with how the JanusGrid should work.
To get around this limitation, I have added the following code in the click handler of any toolbars where there is also a JanusGrid control on the form.
If jsgxYourGridName.EditMode = jgexEditModeOn Then jsgxYourGridName.Update
This way any changes are immediately applied to the current row.
If this does not help, then I have also seen problems where the recordset that is bound to the grid gets out of sync with the internal recordset in the grid. You can check this by comparing the bookmark of the grid to the bookmark of the recordset.
Ie. mrsYourRecordset.Bookmark = jsgxYourGrid.ADORecordset.Bookmark
At one point I may have also used something like this.
jsgxYourGrid.ADORecordset.Bookmark = jsgxYourGrid.RowBookmark(jsgxYourGrid.RowIndex(jsgxYourGrid.Row))
Finally you can try setting a breakpoint in the BeforeUpdate, RowColChange and/or AfterColUpdate events of the grid, to see what record the grid is really on when clicking on the button.
It depends whether the button is internal to Janus GridEX or not. If it internal then just about the only thing you can do is look at the events the control exposes to see if there a sequence that can let you know that this problem occurs. Then you can try to take corrective action by restoring the row you moved to and put the edit in the row you left.
If the button is external to Janus then you can use the debug mode to trace sequence of statement that control the transfer of focus to the next row. It could be something out of order or a side effect of the particular sequence of commands. I have run into both with different controls.
Remember that you can edit while in debug mode so you can try different approaches and test until you find one that works.