C / C++ / MFC

31-Jul-02 18:45

Yet Another List Control Question

i'm doing a subitem edit on a report-style list control. when the user clicks on a subitem, i put an edit control on top of the list control and the user deposits (types) his junk.

the problem is that the list control holds onto the mouse - you can't mouse-select anything in the edit control. so, i came up with two choices:

1. do a SetCapture/ReleaseCapture thing for the edit control. SetCapture when editing starts, then Release when it loses focus or the user hits Enter. i think this is overkill.

2. disable the list control while the edit control is up. this is ugly, since the list control goes gray.

so, my questions are:

1. if i do #2, is there a good way to control the disabled appearance (maybe just the background color?) or the list control, without doing an owner drawn control?

2. is there another way to make this work?

this is on an Explorer context menu extension, so i don't want to use a full-blown grid control.

-c

To explain Donald Knuth's relevance to computing is like explaining Paul's relevance to the Catholic Church. He isn't God, he isn't the Son of God, but he was sent by God to explain God to the masses.
/. #3848917

Nish Nishant31-Jul-02 19:33

Nish Nishant

31-Jul-02 19:33

Chris L

This is not an answer to your question. But I am amazed at your ability to create all kinds of nifty custom controls. That really is your speciality.

I must say that of all the custom control stuff on CP yours is the best in my opinion [though I am sorta biased by the fact that I don't think much of those fancy buttons and menus]. I always feel that having a multi colored tooltip or a super-fancy button isn't as useful as having a control that actually does sosme stuff. Like a font selectiopn combo for example which is a lot lot more useful than say a combo box that looks like it walked out of cartoon network.

I raise my hat to you Losinger

Nish

Author of the romantic comedy

Summer Love and Some more Cricket [New Win]

Review by Shog⁹
Click here for review[NW]

C^hris L^osinger31-Jul-02 19:45

31-Jul-02 19:45

thanks man.

sadly, i feel that the Clean UI Purist is going the way of the Command Line Purist.

Flash is what the kiddies like

-c

Shog⁹31-Jul-02 20:02

Shog⁹

31-Jul-02 20:02

Chris, it's late, so i may have read this totally wrong, but how about just doing a ReleaseCapture() on the list control prior to displaying the edit control? I'm assuming you're doing this in response to NM_CLICK and not LVN_BEGINLABELEDIT to make it obvious that the cell is editable (not requiring the user to double-click).

Another possible solution, one that i've used and works very nicely (although it takes a bit more effort) is not to wait for the click at all, but instead to float the edit control as soon as the user moves the mouse cursor over the cell. This lets the edit control behave exactly as it would be expected to, without any subclassing.

---

Shog⁹
If I could sleep forever, I could forget about everything...

C^hris L^osinger31-Jul-02 20:04

31-Jul-02 20:04

how does this handle mouse selection of text in the edit control?

i think if you have full-row select enabled, the list control eats all the mouse clicks somehow.

-c

Shog⁹31-Jul-02 20:46

Shog⁹

31-Jul-02 20:46

Chris Losinger wrote:
i think if you have full-row select enabled, the list control eats all the mouse clicks somehow.

??? I stopped and did a quick test app, the list control doesn't seem to be doing anything that nasty... You're using an edit control which is a child of the list control, right?

---

Shog⁹
If I could sleep forever, I could forget about everything...

Re: Checks in a list box...

Roger Allen1-Aug-02 2:52

Roger Allen

1-Aug-02 2:52

I do the same in many list controls in my apps. When the user double-clicks an item I identift it and place an edit control on top of the list control. As long as I made sure it was top most, I never had any problem with the mouse not being able to select text etc in it.

m_EditList.SetWindowPos(&wndTop, 0, 0, 0, 0, SWP_NOMOVE | SWP_NOSIZE | SWP_SHOWWINDOW);

This code to edit and item is not within the list control itself, its added into the class that has the lst control

Roger Allen
Sonork 100.10016

If I had a quote, it would be a very good one.

Checks in a list box...

Baatezu31-Jul-02 18:32

Baatezu

31-Jul-02 18:32

Can anyone point me in a direction of how to add Checkboxes into a list box?

C^hris L^osinger31-Jul-02 18:46

31-Jul-02 18:46

use CCheckListBox

-c

Re: Checks in a list box...

Baatezu1-Aug-02 8:42

Baatezu

1-Aug-02 8:42

Thanks for the pointer there... Now I go on to the otehr problem I always seem to have, The Create function for CCheckListBox has a parameter that calls for a CWnd for a parent window. I am using the Dialog editor and I don't know how to get a CWnd for that, I have the HWND of the dialog box, but not a CWnd.
Can anyone point me to how to get that?

Quinn

Re: Checks in a list box...

C^hris L^osinger1-Aug-02 9:01

1-Aug-02 9:01

if you're using the dialog editor, you probably don't need to worry about Create.

put a normal list box on your dialog. then using ClassWizard (or ctrl-dbl-click from the resource editor) make a CListBox member variable attached to that control.

then, go into the header file for that dialog and change the CListBox to CCheckListBox.

now you can use that member variable to control your listbox.

-c

Re: Undo implementation???

Undo implementation???

alex.barylski31-Jul-02 17:03

alex.barylski

31-Jul-02 17:03

Just curious how do you implementent UNDO/REDO capabilities in your projects...?

Currently i've been thinking about an idea using templates for implemententing this functionality. Basically drop the object into your code and call your funcitons in reverse order for an undo effect and visa-versa, my object takes care of the rest.

However I started looking for examples of UNDO/REDO and found only a few which weren't very helpful, i'd like to know how others have maybe done this in the past and possibly will do so in the future.

So anyways...how do you do it...?

Cheers!

"An expert is someone who has made all the mistakes in his or her field" - Niels Bohr

C^hris L^osinger31-Jul-02 17:14

31-Jul-02 17:14

1. make an object that can encapsulate a single change from one state in your data to the next. the info in this object has to be complete enough so that you can use it to go from state N to state N-1.

ex. if you're writing a text editor, each keystroke could create a "state" object that holds the newly-entered keystroke and the cursor position. that way, to undo that state, remove the character at the cursor pos.

every action that changes the state of the data must be recorded, and you must be able to apply this info to go back to the previous state. this may mean copying the whole data set, if the changes are drastic (ex. resizing an image requires that you store the whole image, since you can't reconstruct from the new image).

2. make an undo stack and a redo stack

3. at each state changing event, create a new state object that records the changes you are making to the data (keystroke, and cursor pos, for example) and push it onto the undo stack. clear the redo stack.

4. for an undo, pop the top object off the stack and use the info therein to undo the action (ex. remove the char at pos X). push the object you just popped onto the redo stack.

5. for a redo, pop an object off the redo stack, apply its changes in a negative way (whereas the undo stack removed char X at pos Y, the redo stack will add char X at pos Y). push tat object onto the undo stack.

this will do unlimited undo/redo.

see my colorizing text editor for a working example.

-c