I am trying to achieve something like this BlackBerry 7.1:
But so far I couldnt find or come up with a way to achieve something like this. All I could find was "BlackBerry - TreeField with Checkboxes?" but this really is not what I want since selecting the parent checkbox does not select all of the child checkboxes and whenever I want to select a checkbox I have to deal with an extra menu. Is there any other way to achieve this ?
The indentation is feasible, and the logic, you'll have to craft it on your own.
You could set a FieldChangeListener on every checkbox field so that you can detect when a checkbox have been checked/unchecked. If the parent is checked or unchecked, manually call setChecked over each children field to check/uncheck them. For the children, when one is unchecked, uncheck the parent.
This is the basic logic for a single nesting level (parent and children) Make sure to check in the listeners that the event firing the update of the binded checkbox fields is user generated (not programmatic), because the change listener is also called back when you programmatically call setChecked. If not taken into consideration, you'll run into undesired propagation and infinite loops. Of course, if you had more than one level of nesting, then you'll need to care about programmatically fired events.
Related
I'm trying to create a wrapper component for material button-toggle-group. I should add a lot of custom styling for it, so it makes sense to do this in a component so I can import this component later rather than doing it every time. However, I've hit a snag. It is only possible to click the button one time, and then it is checked forever. Also, all buttons can be checked at the same time. What I'm wondering is:
How do I change the selected button when option is selected?
How can I use the boolean in the dataset to set one of the buttons to checked by default?
Also, how can I limit it to one selection at a time? I tried setting the "multiple"-parameter to false, but this does not seem to work.
I have provided what I have so far in a Stackblitz - for some reason this is not loading the material theme properly, but you can still see the problem and what I have so far:
https://stackblitz.com/edit/angular-b7rxxq
A mat-button-toggle-group is intended to be a group of several buttons... because your loop is on the mat-button-toggle-group you are creating two groups each containing one button.
Remove your loop from mat-button-toggle-group
<mat-button-toggle-group (change)="optionSelected($event)" multiple="false" [name]="label">
Add it to the mat-button-toggle so you have a yes and no in one mat-button-toggle-group... also use [checked]="option.value to default the value
<mat-button-toggle i18n="{{option.i18n}}" [value]="option.value" [checked]="option.value" *ngFor="let option of options" style="margin-left:15%">{{option.displayValue}}</mat-button-toggle>
Please Note: once your options are in a single group, only one will ever be selected at a time... once selected you cannot deselect... you will need to do it programmatically if you need the ability to deselect.
Stackblitz
https://stackblitz.com/edit/angular-rmn4k4?embed=1&file=src/app/toggle-wrapper/toggle-wrapper.component.html
My requirement is to create a customlistfieldmanager by extending verticalfeildmanager, I am not able to figureout how to do this?
I am not able to understand why my manager has asked me to use this method.
any sort of help is welcomed!
It's possible that he's asked you to do this because of the most limiting factor of a normal ListField: you're stuck with uniform heights.
What you'll need to do is have a parent container that is a scrolling VerticalFieldManager. Inside of that will be custom Managers that can handle the same functionality as the row would in a ListField. It needs to accept focus and fire off an event when it's clicked. You'll also need to keep track of what item number it is, so that when it's clicked it knows how to notify any listeners about which one was selected. Also, the parent VFM will need to be able to keep track of which "row" is currently selected -- in this case which one has focus.
Edit for comment
If you add a NullField into each of them it can accept focus but won't actually show up as anything. To determine if a "row" (the Manager) has focus, you can use getFieldWithFocus() on that Manager and the one that doesn't return null is the row that is selected. You will probably also have to do some custom painting to draw the selection highlight
You will have to dynamically add and remove custom elements from your CustomListFieldManager as you add and remove elements from a VerticalFieldManager.
Your manager asked that because he want you to learn how to handle custom object to understand how to use managers.
I have a TcxGrid which consists of a master TcxGridLevel and 2 child TcxGridLevels (all of which use a TcxGridDBTableView). I would like to hide one of the child levels depending on the value of the master level record values. How do I go about this?
Here is a link to DevExpress describing what you want:
https://www.devexpress.com/Support/Center/Question/Details/Q96738
But this has some disadvantages in my opinion. First it is quite slow with bigger datasets. Second it comes to "flicker" when your master level changes frequently and the grid has to be redrawn. Maybe it is possible to set a filter to your detail-dataset so the details are "empty" when your nmaster has the correct condition. There is a property in TcxGrid to hide empty detail-tabs automatically.
Somewhat out of context but in case the link goes dead again:
1) How can I trigger Level3 OnGetGridView, because Level3 View was not change as I was expected
The OnGetGridView event is raised only once when the detail is first expanded. After the event handler has been executed, the specified GridView’s clone is created and cached so that the event doesn't fire when expanding the same master record next times. If you need the event to be raised later, you can clear all detail clones by calling the master DataController’s ClearDetails method or ClearDetailLinkObject methods.
You can find this information in the "TcxGridLevel.OnGetGridView" topic of the ExpressQuantumGrid's documentation.
2) I am also changing Level2 and Level3 Caption for every Gridview that it showing, but the changing is not automatically, sometime the Detail View need to be close and open again to make the Caption change.
If we're not mistaken, you change the Level's Caption in its OnGetGridView event handler. If so, the new caption isn't applied immediately because painting of the corresponding element isn't completed. As a workaround, you can perform a "delayed" operation by posting a custom message. I've attached a sample project to illustrate this approach in action. Hopefully, it will serve your needs, and adapting it won't be aproblem.
On my main form I have a TPanel containing buttons that act as a toolbar. I want to clone/copy this toolbar and the buttons and their functionality to a second form.
Cloning the menu was simple using newmenu.merge(mainmenu). That was an excellent shortcut to duplicating a Tmainmenu.
But I am at a loss on how to easily duplicate my toolbar without having to manually assign the events and keep a timer to compare and track which buttons are enabled and disabled in comparison to the real mainmenu on the main form. Depending on what the application is doing the main toolbar buttons will be enabled and disabled at various times.
Any ideas here? Thanks for any suggestions or tips to make this easier.
Duplicating the controls
In the Form Designer, select the panel and press Ctrl+C to copy it and all its children to the clipboard. Go to the second form and press Ctrl+V to paste.
If you're still working on the design and want to keep it consistent between both forms, then create a TFrame and design your toolbar layout there. Then put an instance of that frame on both your forms. Changes to the frame design will be reflected in the forms.
See Working with frames in the help.
Making sure both sets of buttons are enabled consistently
Create a data module. Put a TActionList on it. Add an action to it for each button on your main form. Assign event handlers to the actions' OnUpdate events. In them, set the actions' Enabled properties. Finally, assign each button's Action property to refer to the corresponding action object. The buttons will automatically get enabled and disabled with the actions. No timer required.
Furthermore, you can handle the actions' OnExecute events, too. Clear each button's OnClick property, and then move the button's OnClick code into the corresponding action's OnExecute handler. It will automatically get called when you click the button, even though the OnClick property is empty.
When you assign the Caption or Hint property of a TAction, the corresponding properties of any associated controls also change. Likewise for images, if the control supports them. Actions can be assigned to menu items, too.
See Using action lists in the help.
Acting like a toolbar
Just use TToolbar. That's what it's for.
Or, once you're used to actions, put a TActionManager in your project and use it with TActionToolbar and TActionMainMenuBar. See Organizing actions for toolbars and menus in the help.
Are the buttons attached to actions? If so, you can use the OnUpdate event of the TActionList to specify what should and should not be enabled. If not, it isn't too much work to convert to using actions.
If you go this route to convert to using a ActionList, consider putting the ActionList in a datamodule where different units and forms could reference it.
You can Use ClipBoard Object For Copy Your Panel.
Clipboard.SetComponent(Panel1);
Clipboard.GetComponent(Form2,GroupBox1);
Before Delphi 2006 (I think) introduced the TFlowPanel and TGridPanel, I did a control that was similar in concept. It still does a couple of things those controls do not do, and when upgrading my code to Delphi 2009, I decided to add a couple of enhancements to that as well.
Right now, the order of the child controls is determined by their creation order. The FlowPanel and GridPanel show a better way with ControlIndex and other filtered properties, but I was wondering if there is a way to handle drag and drop reordering in design-time? As far as I can tell, dragging an edit control and dropping it onto my panel doesn't call anything that I can access at design-time.
I was half-fantasising about a way to either detect the drop operation directly, or to perhaps detect when a control is moved so I can determine where it should go.
Any ideas?
Update:
OK, got it working. The container control was already overriding AlignControls to manage the placement of the controls. When you drag the nested control and drop it, AlignControls is again called. I then compared the new coordinates of the control with the other controls in the list and moved it to the appropriate position.
There were a couple of problems that I had to work through (mostly related to the many calls to AlignControls) but the basic concept is simple enough. Thanks to all the commenters for all the help.
You can't drag a control that's already on the form and drop it onto your panel. Dragging is only for moving a control, not for changing its parent. To change the parent, cut and paste.
If the control is already on your panel, and you want to move it to another position on your panel, then the panel can control the layout by overriding the TWinControl.AlignControls method. When a control is moved, its SetBounds method is called, and among the things tha happens is that it calls AlignControl(Self) on its parent window. That calls AlignControls. Look in Controls.pas, and you'll see that that's a complicated method, but it's what is responsible for the layout of the children on a control, and that's exactly what you're planning to change.
Perhaps some of these suggestions might help.
You can re-parent a control in the designer without having to do cut-and-paste. View the structure pane, and simply drag the visual control to the node of another parent in the structure pane. If you have things in a flowpanel, drag everything out of the flow panel and drag them back in the order that you want them to be.
(You can re-parent ANY visual control this way, without changing anything other than its parent. I highly recommend doing it this way.)
You can view the form as text, and move the declaration order around in there -- but obviously you'll need to be careful when editing the "resource" file directly.
You can set tab order in the designer, so you could make a different control based on tab order that works as you want. You can right click on the form and change the creation order of the non-visual controls, but that doesn't work with visual controls.
Have you tried to write an "OnDragDrop" event for your grid component, where you check if your component is in design mode?
I haven't written such a component yet, but I don't see why the event shouldn't trigger.