I have implemented the VerticalSeekBar using this unbelievably simple solution here: How can I get a working vertical SeekBar in Android?
The problem is, I can't seem to set an onseekbarchangelistener in my UI Activity that uses this class. I can't for the life of me understand how to do this. I can do it from within the VerticalSeekBar class: if I add code inside the onTouch() method, it works.
However I need an onTouch listener in my Activity.
P.S. is there a particular reason why Android doesn't have a native vertical seekbar? Considering most phones are naturally portrait-mode devices, it makes sense to have bars running along the the length rather than the width of the screen. I have tried many VerticalSeekBar solutions from stackoverflow (love this site!), but the only solution that centers my SeekThumb graphic is the link supplied above. I have been working on getting a perfect vertical seekbar for months now. Any help would be a humansend!
in VerticalSeekBar class, comment out this whole part:
#Override
public void setOnSeekBarChangeListener(OnSeekBarChangeListener mListener) {
this.myListener = mListener;
}
instead you can do this
SeekBar sb = (SeekBar)findViewById(R.your.id);
sb.setOnSeekBarChangeListener(this);
Eclipse would underline it and ask you to implement onseekbarchangelistener, you do that and implement the methods and you are good to go
Good Luck !
Related
I'm building in content inside of a NSTableView, but when I compile and run, it cuts off the top half of all the content within the NSTableView. I'm brand new to the Swift language so I am quite lost here. I can provide further examples as necessary. Is there something simple I am missing first or is this more specific to my use case?
I can quickly give you a few directions to go looking for help.
Firstly the Apple Documentation for it. https://developer.apple.com/library/mac/documentation/Cocoa/Conceptual/TableView/PopulatingView-TablesProgrammatically/PopulatingView-TablesProgrammatically.html
You may note that there are essentially two ways of populating the table view, programmatically by implementing the methods of NSTableViewDataSource and NSTableViewDelegate protocols. And by using Cocoa Bindings. I recommend, as a beginner, to use the first option and look at either example code or videos that use these protocols.
Secondly, this may be just a UI issue in your storyboard, make sure your constraints are set properly. You may just have some weird behavior going on here with other views.
Unfortunately, I cannot give you more help without code snippets or more information
I'm new to RCP and I'm trying to create a new View or Editor. At the current state I'm extending ViewPart.
The Layout I want to achieve is a SashForm where both sides have a CTabFolder. One of the sides of the SashForm is basically a MultiPageEditorPart. One of it's tabs should be an editor for a specific language with syntax highlighting and similar features. From what I understand I could extend AbstractTextEditor for that (and maybe use it as one tab of a MultiPageEditorPart).
If I try to achieve this layout with a ViewPart as top level container which contains a SashForm, I can't add an EditorPart to one of the sides of the SashForm. Of course I could implement this editor from scratch as Composite but I want to avoid that.
I am also willing to use an EditorPart or MultiPageEditorPart as top level container but then I'd have to find a way to get the SashForm layout working. The whole editor should be splited first and then each side should have tabs.
Does anyone have an idea how to solve this?
If anything is unclear please ask. I've got the feeling I've put this into words a little complicatedly.
I think you should just make a ViewPart that has a text editing component of some kind on the left, instead of trying to find a way to use an EditorPart. All that EditorPart is really buying you is dirty flag management and Save support; syntax highlight and so forth you can add to the text editing component yourself (I was surprised at how few drop-in text components I found while poking around the internet just now; I expected to find "a few" and instead I found "basically none").
You can see one way to do very rudimentary syntax highlighting with a StyledText component here: JavaSourceCodeViewer
To see a more robust implementation of things like syntax highlight and autocomplete, take a look at the class that Eclipse uses for the editing of Java source code: CompilationUnitEditor
I think what you are trying to achieve is quite complicated and might require a lot of extra work. See an editor is not just different controls laid out in some order, but it has a lot of additional features that any editor class expects to work. These include things like selection service and action bars etc, that you will need to hook in to ensure smooth running.
That said, it should be possible to achieve what you are hoping for. You can have a look at the source code of the MultiPageEditorPart itself to see how it converts a single editor into a multi page editor, which is capable of hosting a completely independent editor on each of its pages. You would need to achieve something similar if you want your editor to host two MultiPageEditorParts separated by a sash. If you want to carry on, you should start implementing some stuff and if you run into any problems, post them here. You would be able to get a lot better help then.
You need something like MultiPageEditorSite. Use it for inspiration when implementing an EditorSiteDelegate. MultiPageEditorSite has support for separate keybindings between the pages, for example.
class ChildEditorSite implements IEditorSite {
IEditorSite parent;
public Object method() {
return parent.method();
}
}
Using this class, you can easily do the following in your main EditorPart:
class MyCoolPart extends EditorPart {
public void createControl(Composite parent) {
EditorPart child1 = new MyChild();
child1.init(new ChildEditorSite(getEditorSite()), myInput);
EditorPart child2 = new MyChild();
child2.init(new ChildEditorSite(getEditorSite()), myInput);
child1.createPartControl(parent);
child2.createPartControl(parent);
}
}
Be sure to also dispose of your children correctly when you dispose of your MyCoolPart. Please note that this only works in the most basic of cases. An EditorPart that is a DocumentEditor or that relies on IPersistablePart or implements listeners/adapters for confirming a save is probably going to require a lot more Lifecycle management...
I know there are some questions out there about the GWT ScrollPanel and how it works, but allow me to explain the situation.
I'm working on a project to implement QoS on routers. I'm now at the developping stage of the project and I need to make a webinterface to add protocols such as ssh and http and give them their bandwidth.
To save memory usage and network traffic, I do not use GWT-EXT or Smart GWT. So to set the bandwidths I use a ScrollPanel with an empty SimplePanel in it (which is way too big), leaving only the scrollbar.
Now here's the problem:
I want each scrollbar for each added protocol to start at the bottom, not the top. I can get it working through the code if I manually move the scrollbar first, then any function works, like a scrollToBottom(), or a setScrollPosition(). If I want to move scrollbars through code before moving the scrollbar manually, however, I can't call a function on it.
(I would post a picture but I can't yet - new user)
Summary:
So if I add a protocol (using a button called btnAjouter), the two slidebars (One for guaranteed bandwidth and one for the maximum bandwidth) for each protocol start at the top. I want them to start at the bottom on the load of the widget.
Is there a way to do this?
Thanks in advance!
Glenn
Okay, my colleage found the solution. It's a rather dirty one, though.
The thing is, the functions only work when the element in question is attached to the DOM. I did do a check with a Window.alert() to see if it was attached, and it was. But the prolem was that the functions were called to early, for example on a buttonclick it would've worked. The creation and attachment of the elements all happens very fast, so the Javascript can't keep up, this is the solution:
Timer t1 = new Timer()
{
#Override
public void run()
{
s1.getScroll().scrollToBottom();
s2.getScroll().scrollToBottom();
}
};
t1.schedule(20);
Using a timer isn't the most clean solution around, but it works. s1 and s2 are my custom slidebars, getScroll() gets the ScrollPanel attached to it.
You can extend ScrollPanel and override the onLoad method. This method is called immediately after a widget becomes attached to the browser's document.
#Override
protected void onLoad() {
scrollToBottom();
}
Could you attach a handler to listen to the add event and inside that handler do something like this:
panel.getElement().setScrollTop(panel.getElement().getScrollHeight());
"panel" is the panel that you add your protocol to. It doesn't have to be a ScrollPanel. An HTMLPanel will work.
You can wrap this method in a command and pass it to Schedule.scheduleDeferred if it needs to be called after the browser event loop returns:
Schedule.scheduleDeferred(new Scheduler.ScheduledCommand(
public void execute() {
panel.getElement().setScrollTop(panel.getElement().getScrollHeight());
}
));
in a définition of a widget, what is a better practice, and why, use the widget himself or the type "higher", example, it's a better practice to do
1) Button myButton;
or
2) Hastext myButton; (and set a button later)
thanks for your answer.
It is usually a good idea to use "higher" types or interfaces. By doing this properly you can hide implementation details. The code that uses an object looks at it as the one of a higher type and it is not important what is actually hiding behind it. This is good because you can easily change an implementation of the object without breaking anything.
For example when defining a panel in an application you should use Panel class instead of its implementation e.g. HorizontalPanel or VerticalPanel.:
Panel myPanel;
Then you can create a proper implementation of it, e.g HorizontalPanel:
myPanel = new HorizontalPanel();
If you then later decide to change myPanel to be VerticalPanel you will not have to change anything in the code that uses myPanel. Everything will work just fine.
However you must remember that you will be only able to use methods available in Panel class. Additional methods defined in e.g. HorizontalPanel will not be accessible. And this is actually what you should remember when choosing the type of your widgets. Your widgets should be of types which provide methods which you want to use.
In your example using HasText instead of Button isn't probably a good idea because HasText has only methods for setting and getting a text and you probably also want to have access to addClickHandler method available in Button and a few more.
So to summarize it is good to use "higher types" but they should not be "too high" to be useful.
The answer to that lies in the Model-View-Presenter pattern, that was introduced in last years Google IO presentation by Ray Ryan. There's also an official tutorial/docs - part 1 and part 2. There are also a number of questions here on SO that cover that topic :)
And a quick answer to your question (that will make more sense once you get familiar with MVP): use interfaces in the Presenter and their implementations in the View :) That way your Presenter stays oblivious to the underlying implementation/Widget you actually used (was it a Button? Or a Label? It doesn't matter, they both implement HasText).
I have posted this question on the Ext-GWT forums, I am just hoping that someone here might have an answer for me!
I am struggling to do something I initially thought was simple but am beginning to believe is impossible...
I have got a "layout template" of sorts - simply consisting of a few GWT DockLayoutPanel's within each other and finally ending in LayoutPanels. GWT's LayoutPanel is designed to size the widget (or Composite) that's added to it to its full size and does so perfectly with pure GWT widgets.
The idea of my "layout template" is that I don't know the EXACT height and width of the very inner LayoutPanel's because I may set certain panels sizes (of the outer DockLayoutPanels) differently when instantiating this template. All I would like is to add a Grid component to one of the inner most LayoutPanels and have it size itself (height AND width) to fit as normal GWT widgets do (works perfectly with a GWT Label for instance).
I am VERY new to GXT (as in I started using it earlier today) and I do realize that GXT builds its Components differently to the way GWT builds its Widgets on the DOM.
Is there anyway to achieve the desired result? I have tried adding the grid to a ContentPanel with a Layout of FitLayout, I have tried AnchorLayout, I have tried adding the grid directly... Nothing seems to work... Any advice or even a push in the right direction would be greatly appreciated!
Thanks in advance!
Xandel
Just a note on this post and the direction I have taken. When I started my GWT project and I was learning the basics and reading through others posts and concerns and advice, the one bit of advice I overlooked initially was quite simple - when using the GWT framework use pure 100% GWT components only.
I initially ignored these fair warnings of fellow developers because in the age of open source tools, and open source projects, one develops the mind set of "Instead of building a tool which will give me certain functionality, let me rather see if someone else has done it already". This mindset speeds up development and almost standardizes projects and methods of implementation.
However, I have found over the last two months, that when working with GWT it is best to not follow this principle. Maybe because its not as widely spread as other frameworks, or demands a very certain type of coding style but non the less my search for a (simple, sortable, JSON loadable) grid component and (validating, neatly styled) form component has been nothing short of a nightmare.
This isn't because they don't exist. They do. I tried ext-gwt, gwt-ext, gwt-mosaic, and gwt-incubator. It is because many of the components break away from the very simple layout foundation that GWT provides (in other words, the panels that you place the widgets on mostly need to be the panels provided with the tools). This in turn makes mixing components and getting the desired result near impossible. Which in turn breaks away from the let-me-find-a-useful-component mindset.
Just an interesting and final point which I think might be worth mentioning. So due to my realisation of the above mentioned point, I set about to write my own grid and form components. Which I have completed and are working fine for me (obviously, because I wrote them , I don't suspect they will be useful to everybody else). But in the process of writing the grid component, and needing the columns to size and space themselves out automatically once drawn in their parent panel, I found that knowledge of the panels final width is not known until finally being drawn (this happens long after all your code executes). So ironically I set about building a set of panels that communicate to each other, from the parent panel (who ultimately NEEDS to have knowledge of its size) right down to the most inner panels so that when my grid component finally gets drawn, I can fire a method called onSizeKnown(int width, int height) and do whatever sizing is required.
After I completed this I could do nothing but laugh. Because it suddenly became clear to me why all the other GWT components out there require their own panels. I in essence had to do the same to get what I needed working.
So in short, if you are a newbie GWT developer like I was and are (is?) looking for cool stuff to make your project look awesome - this is my advice - if you are going to use an external framework such as some of the above mentioned - use ONLY that framework. Do not mix its components with other frameworks. Learn to love that framework, and build your project from the bottom up using their panels and design methods. If this scares you and makes you feel nervous and limited then do what I did and write your own using pure vanilla GWT components. You will save yourself A LOT of time in the long run by following this advice.
Xandel
This solution is for GXT 2.2.0 and GWT 2.0.4 *
While the original poster has since moved on I recently ran into this issue and thought I would post my solution in case anyone else stumbles on this.
There is no reason you can't add a GXT Grid directly to a GWT LayoutPanel. The problem is that the styling/positioning approach of the two libraries conflicts. Basically it boils down to the fact that the Grid is sized based on its parent's height attribute, which is not set meaning that the grid's body get assigned a height of 0 and the grid itself gets a height equal to that of the grid header (if present).
So the solution is to undo what GXT does once flow has passed back to GWT. Here is a template solution:
class MyGridWrapper extends Composite {
private LayoutPanel widget;
private Grid<?> grid;
public MyGridWrapper(Grid<? extends ModelData> grid) {
this.grid = grid;
widget = new LayoutPanel();
initWidget(widget);
widget.add(grid);
// Set the grid's vertical and horizontal constraints
// ... populate the rest of the panel
}
#Override
protected void onLoad() {
// onLoad is called after GXT is finished so we can do what we need to
// Redo what the LayoutPanel did originally
grid.el().setStyleAttribute("position", "absolute");
grid.el().setStyleAttribute("top", "0");
grid.el().setStyleAttribute("bottom", "0");
grid.el().setStyleAttribute("left", "0");
grid.el().setStyleAttribute("right", "0");
// Undo any height settings on the .x-grid3 element
El mainWrap = grid.el().firstChild();
assert mainWrap.hasStyleName("x-grid3") : "Wrong Element: " + mainWrap.getStyleName();
mainWrap.setStyleAttribute("height", "auto");
// Undo any height settings on the .x-grid3-scroller element
El scroller = grid.el().firstChild().firstChild().getChild(1); // FUN!
assert scroller.hasStyleName("x-grid3-scroller") : "Wrong Element: " + scroller.getStyleName();
scroller.setStyleAttribute("height", "auto");
}
}
The assertions are there to help protect against what is obviously very fragile code so beware that this is a GIANT, GIANT hack.
--
Just in case you're wondering where the GXT Grid's structure is defined, you can find it in a template file in the GXT JAR under com/extjs/gxt/ui/client/widget/grid/GridTemplates#master.html
Have a look at com.extjs.gxt.ui.client.widget.grid.GridView#renderUI() to get an idea of how the grid is built.