I'm trying to create a custom polymer 1 component with a bwu_datagrid inside of it. This component can be resized on-demand, I've seen the "e11_autoheight" and "e12_fillbrowser" examples, but I don't want to rely on "100vh", nor force the parent div to grow to show ALL rows.
Is there a way to permit the datagrid to grow when a parent div is resized but continue to keep the scrollbar if the parent div is smaller than the # of rows?
Any guidance is highly appreciated.
I use for example
dom.window.onResize.listen((dom.Event e) => grid.resizeCanvas(e));
See https://github.com/bwu-dart/bwu_datagrid/blob/44215176ca3443d76b1a0573a25186e97ca7f207/example_/lib/e12_fillbrowser/app_element.dart#L86
There might be other reasons for the container to resize than a resized window , but there is no way to get resize events from elements (at least not from all browsers).
In this case you have to find other means to invoke this code. For example if you have a splitter component, you would get some drag events or similar.
Related
The Grid widget in Vaadin 8 & 10 offers a method to get a Set of the currently selected items: Grid::getSelectedItems.
In a similar vein, I would like to get a collection of the items that are currently visible to the user in the Grid. Say my Grid widget holds 10 items, but only 5 are viewable because the Grid widget is too short to display them all. I want to know which of the five can be seen by the user.
This is not trivial task, I have something similar, but not exactly this case before. First of all, I would I would create custom Layout component, e.g. by extending CssLayout in similar fashion as has been discussed here ( How to make UI receive scroll events ) in addition to reporting scroll events I would report the position of the layout on the viewport (see http://www.gwtproject.org/javadoc/latest/com/google/gwt/dom/client/Element.html ). Yes GWT and client side development is required.
I would use this layout as wrapper for the Grid, i.e. Grid would be in the layout. You could extend the Grid component as well. But I think doing the layout wrapper gives you nice tool that you can use with other components as well for which you need to determine, whether they are actually visible or not.
This way I can then calculate which portion of the layout is in the viewport. As you see, there are number of cases here, e.g. only bottom of the Grid or top of the Grid is visible. Then I need to know row-height, header height, etc. That enables me to calculate how many rows there are visible. I hope you get the idea. The outcome for the generic case will be rather lengthy piece of code when all possibilities are enumerated. This calculation you can do on server side.
I'm working on a responsive, full-width layout and I need to do some element processing when the size changes. This has to not be linked to the window, as the size can change without the window size being modified e.g. changing number of columns.
I'm working with AngularDart directives and components and it would be nice to have a directive say, "resizable" which implements such an event for the element.
I've come across the attributeChanged() method in the Dart Element class but don't really know how to tap into that without creating custom elements.
Problem
I am having problems with my sortable list with several items of various height. The problem occurs when I'm trying to move a larger item to the first or last position (which both have smaller objects). If I succeed currently depends very much on where on the larger item I click and start dragging.
If I want to move the item to the smaller bottom position I must click close to the bottom of the item for it to work, and if I want to drag it to the top position I must click closely to the top. But I want to be able to drag the item by clicking anywhere.
Some additional information
The items cannot be dragged outside the parent and the parent is only as large as it has to be and a scroll appears if it's larger than it's container. So it seems that I cannot drag the larger item past the first(smaller) item if I don't drag it in the top part of the item.
I've been trying to fix this by using cursorAt and using top:0 and another test using bottom:0 But it doesn't seem to make any difference (so I might have misunderstood how to use it). I am currently using tolerance: pointer.
I can bypass the problem of not being able to drag the larger item to the last position by temporary during the sorting increasing the height with the height of the dragged item. But it doesn't always work and its not a very good solution. And the problem of not being able to drag it to the top still appears?
I cannot change the JQuery code as in jquery-sortable-with-containment-parent-and-different-item-heights
Question:
How can I drag a larger item to the top or bottom position while allowing the user to click anywhere on the item?
Thanks for your help!
This might not solve your problem, but I thought I'd share the results of some experimenting I did today. I needed to make a sortable photo gallery with inline-block pictures of varying widths, and found that moving wider photos would be really hard work because the placeholder was smaller than the item I was moving. I ended up using this:
container.sortable({
placeholder: "photo placeholder",
start: function (event, ui) {
ui.placeholder.width(ui.item.width());
}
});
The custom placeholder classes are there to ensure the placeholder isn't hidden by default, and the start event ensures that the placeholder is the same width as the item you're about to move. This worked very well for me, and in your case, substituting height for width might work.
I also tried using containment as you have done, and found that it sometimes makes things much harder depending on the items in the row. Like you have explained, including tolerance: "pointer" helps to alleviate the issues, but if possible, removing containment generally makes the UI more forgiving.
I have a Label and a Progess Indicator in my Vaadin indicator. It is dynamically made visible in the UI. There is a Tree below this Progress Indicator.
When the program dynamically sets the visibility of the Progress Indicator to true, the tree shifts down and the UI shakes due to the shifting.
Is there any way to make a Vaadin component occupy it's space, even if it is invisible and hence, when made visible it must not try to borrow space from other UI components?
What I am looking for is a feature similar to setRendered(true) in flex and actionscript programming.
Thanks for your help.
Finally I got an answer to my question. I just replaced the invisible components with a dummy visible label with no text.
And used it alternatively to switch between visible and invisible.
I asked the question in the Vaadin forum, and here's the response I got, from Kim Leppanen:
With Vaadin 7, if you set a component's visibility to false, then the component's information is not sent to the browser at all - it is just as if the component wouldn't exist in the layout at all.
I can quickly come up with two solutions. If you know the size of the component whose visibility you want to toggle, then you can use placeholder components - such as a Label. Put a label with the correct size in the place where you want the component. When you want to set a component as visible, then replace the label with the actual component.
The second option is to use css. Apply the css attribute "visibility: hidden" for the component you want to hide. Note that the component is not "truly" hidden. Let's say that it is a button. A user could still inspect the DOM tree and see the button in the code, change the visibility of the component on the client side (eg using developer tools or firebug) and then see and use the button as if it would be visible in the layout.
I am putting it here because people might add some more useful answers there. For a detailed explanation please see this.
Use this following example to the component you want set invisible but keeping its occupied space:
Image home = new Image();
home.setSource(HOME);
home.addStyleName("visibility: hidden");
OR
home.addStyleName("visibility: collapse");
We have developed a software. In this software we are show and hiding a few controls on various input screens depending on various situations.
When we hid a control what happens is that the space occupied by that control is left as it is and layout looks very bad at times esp. in screens that have larger numbers of controls. Our client does not like this and has asked us to do something about this.
My question:
Is there some way by which we can create Fluid Layouts so that when a control is hidden the rest of the controls automatically adjusts themselves to fill the empty space left by the control hidden and when the control is show they should automatically make way for the control and adjust themselves accordingly.
I know we can achieve this by coding but that will require a lot of code in each screen for adjusting the layout. I am looking something which will reduce coding in each screen as there are 80+ screens.
Please suggest some way which is less error pron and can get rid of unnecessary coding in each input screen.
I think your best option is to use a component that handles the layout of your vcl controls on your form in runtime (depending on the conditions that you define). I recommend you try the Devexpress ExpressLayout Control
you can find two great demo videos here
ExpressLayout Control - How to Customize Layout Views
ExpressLayout Control - Create and Customize a Simple Layout
(source: devexpress.com)
You can check these features
Auto-Management - Control groups and individual control elements are automatically managed by the Layout Control. You never worry about pixel-by-pixel positioning.
Form auto-sizing - The form can be automatically resized to fit its contents best.
Bye.
Now, I'm not sure how complex layout you have, but I guess you can use TFlowPanel and/or TGridPanel for this. Flowpanel has a nice handling of components that change visiblity. I'm not sure how well gridpanel handles the same...
What kind of controls are you dynamically hiding, and what do you mean with auto fill space?
I do not know if it is as this simple: place controls on panels, and use align alTop/alClient/alBottom. When you hide a panel, all other panels will move automatically up.
One problem though: if you want to show a panel again, the order of panels can sometimes be screwed up... Can be fixed by manually setting .Top property, or "hide" by setting .Height := 1;
What I would do with a complex layout is actually split it up into several tabs. This has two advantages. It simplifies the form layout, and allows you to show and hide whole tabs depending on choices made in other tabs.
Raize Components have a TRzFlowPanel UI component. Does exactly what you're after.
Use TRzFlowPanel to put an empty flow panel on a form. The major difference between a traditional panel and a flow panel is the way in which controls are placed. With a traditional panel, you place a control (such as a button) in a specific location. You can freely move that control to any location within the panel using the mouse. In a flow panel, each control is placed in a specific location, regardless of where you place it with the mouse. The automatic location is controlled by the FlowStyle property. For example, using the default FlowStyle property of LeftRightTopBottom, the first control you add to the flow panel snaps to the top left corner. The second control that you add snaps next to the first control, and so on.