I've found three functionalities in VLayout:
vLayout.isDrawn()
vLayout.isAttached()
vLayout.isCreated().
These functionalities are inherited from its super classes. Can anyone tell me the difference between the three? Or when the VLayout is said to be drawn, created, attached?
Thanks in advance.
To my understanding this three properties are inherited from different superclass:
isAttached from Widget
isCreated from BaseWidget
and isDrawn from Canvas
We are going from close to the dom to a DHtml object(the canvas)
To me created mean the Widget had been instanciated, attached would mean that the rendered html elements are attached to the dom and drawn when the whole set of element representing a widget is on the screen. It's only my perception, I never found any details on that. These properties don't seem to be for high level operations...
Regards
Alain
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 trying to make a simple list editor in Dart, with Polymer, but I have some problems.
I will start by showing a screenshot of what it will look like.
design of the app
The left drawer is filled dynamically at run-time (a rest api is used to get the items).
The items are "MLayers" and clicking the button should add the corresponding "Layer" to the right part of the app.
The thing is I can't find a way to do this! I tried to launch a customEvent when the button is clicked but the method responsible of adding the new layer need the layer name (and I can't find a way to add parameters to customEvents...).
What do you recommand?
The structure of the app is:
mainApp
_ Drawer
__ MLayer
__ Layer
I think the class responsible of adding Layers should be the Drawer (in fact it contain the drawer AND the content). The Layer constructor should use the name (or ID) of the MLayer to display corresponding properties (lets say the MLayer "Dense" has properties "name" and "size"; the Layer is in fact an instance, while the MLayer is the maquette).
Thanks for the read!
EDIT: as requested, here's the code
Ok, so I didn't find the right way to do it, so I simply broke encapsulation by adding a property "MLayerDrawer" to my "MLayer" object and calling its method...
I'm still open to suggestions because this clearly isn't the right way to do it, it just work but is really dirty.
Why everything has absolute position?
I'm trying to make a Panel with a title, the title is behind the child nodes of the panel, because the children are in absolute position.
How I can build custom views if they not respect my layout? I want control in where the childs are place.
I don't like this approach could someone clear my mind?
Here is the simple code example:
class MyPanel extends View {
String title;
MyPanel() {
}
#override
Element render_() =>
new Element.html('<div class="v-shadow"><div class="v-title">$title</div><div class="v-inner" id="$uuid-inner"></div></div>');
}
This is the result screenshot, the title is a dashed blue border
http://i.stack.imgur.com/pPrRD.png
Yes, the absolute position is designed on purpose. In short, it ensures the views in Rikulo are 100% controllable. For more about the philosophy behind it, please refer to here and here.
Unlike CSS, the position is controlled by your application (in Dart) or by use of the layout manager, such as linear layout and anchor layout. Of course, you can provide your own layout too.
If CSS layout is what you want, you can embed the HTML fragment with TextView.fromHtml.
Notice: you HTML fragment of MyPanel shall be controlled by CSS, since only the view (i.e., MyPanel in your case) is absolute positioned. The tags generated by render_() won't be.
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.
I try to convert an existing OpenGL-Application from VCL-based forms to FMX-based forms in C++ Builder XE3.
For this purpose I use the handle of a Firemonkey-form to create the OpenGL device context and make this form a child of another form to mimic the panel inside the form which I had in my VCL-based application.
The problem is now that after a resize-event or in general after calling Invalidate() the form is rendered with its background. This causes a flickering or even worse: sometimes the background is shown instead of my OpenGL rendered scene.
How can I prevent the repaint of the region at the position of my Firemonkey-OpenGL-form. Alternatively, can I define an Ownerdraw-function or something else?
Please note, that it is no option for me to use a Firemonkey-3d-Form.
Have tried giving the form a transparent background? Then you can paint whatever you want 'over the top'.
The quick way is to set the forms Transparent property to True, but this creates issues with ComboBoxes.
Another way is to place a TRectangle on the form. Set it's StyleName to 'backgroundstyle'. Set it's Fill.Color to claNull. Set Stroke.Thickness to 0. This will replace the default background styling for the form.
If you want to paint your own borders too you'll need to investigate non-client area styling but I don't have a pointer to a good resource at present.
After hours of experimenting I found the solution: The "TCommonCustomForm" has the needed properties: (1) it does not draw itself, (2) it has a handle which can be used for OpenGL initialization.
I hope this information will help others.