I'd like to create something like this:
I can make a custom controller (maybe using a `NSCollectionView ) but it's a lot of work. Does anyone know a library or workaround in Cocoa?
The basic Cocoa machinery for the typical app is NSPredicate (to filter your content), and an NSPredicateEditor control.
To get fancy (have the field grow and shrink, pushing content down as rules are added), you'll need to manage / animate the views yourself as predicates are added / removed. You'll observe the view for frame changes adjust/animate the "search filter" view in your app to push down the content, etc.
Even fancier: If too many rules are added, there won't be any more room for content, so you'll need to figure out a sane limit, at which point you stop growing the view and let scrolling take over.
Related
I'm trying to understand how autolayout works under XCode6, but there's a lot of mysterious things that runs away from my mind. Autolayout and constraints philosofy can be very hard to learn, but I realized that life can be easier using these tools...
For your information, I need to build a chat view with a table (the messages) and a view containing a text field (the send message pane) nested in a UIView that is again nested in a UIScrollView, so I can shift up the scroll view as the keyboard appears under the textfield.
I read a lot of tutorials and watched a lot of video until I found the useful tutorial Using UIScrollView with Auto Layout in iOS. There's a Xcode project in Github of what the tutorial explains, too.
In his tutorial, Mike Woelmer tells that
One of the big pain points with the old way of setting up a
UIScrollView was communicating the content size to the scroll view. It
was fairly straightforward to calculate your content size if the
content in the UIScrollView was an image. But it was not as easy if
your scroll view included a mixed bag of buttons, labels, custom
views, and text fields. Lengthy code adjustments were needed to
reflect constant changes in device rotations and phone size
differences.
So Mike explains the way to adapt the UIView, using placeholder and forcing the view inside the scrollview to fits the device's screen, creating in viewDidLoad some NSLayoutConstraint:
The solution is to look outside the scroll view and attach a
constraint to the view controller’s main view. This cannot be done in
interface builder, so we will have to write some code. Interface
builder is still complaining, though, so we have to add a placeholder
width constraint to make it happy.
I tried to use parts of the code of the tutorial for my project, but I cannot get a working view controller for my needs (I always get errors). Which is the best approach to do this? Am I on the right road?
Last but not least, I'm italian, so pardon for my english. If something is not clear enough, please leave me a comment.
Basically you have to set both alignment and size constraints in order for Autolayout to take care of the rest for you. If you don't provide enough information you get warning. If you provide conflicting information you get errors.
You need basically to provide enough information for Autolayout to calculate the UIView frame property (i.e., x-position, y-position, width, height).
For example, by providing the distance constraints from the top, right, bottom, and left edges, Autolayout has enough information to draw that UIView's frame rectangle. But you could also provide just the distance constraints from the top and left edges and then provide a size and height constraint.
You can also configure the key constraints you need and then click 'resolve auto layout issues' and choose 'add missing constraints' though sometimes it doesn't give you what you want. It is better to understand that how Autolayout accomplishes what I described above.
If you mess up, it's usually easier to clear all the constraints and start over. Do it a few times and you'll get the hang of it.
I know the title is a little confusing, but the best way to describe what I'm after is by running the Weather metro app on the Consumer Preview; as you scroll horizontally, you'll note that the section headings kind of move around and stay on top of the relevant content, and then fade out as you cross over into a new section. (The main background for the first section also kind of does this)
My question is, how would I go about replicating this behavior in a WinRT app of my own? Are there any existing controls I can leverage or would I have to essentially rewrite it all?
This looks just like a ScrollViewer - you would handle the ViewChanged event and depending on the scroll offset - change the opacity of overlaid static TextBlocks and completely hide the ones that scroll once you cross specific tresholds. I don't think there is anything like that that does it, but I can build it.
There is a problem with sencha touch 2.
I am trying to understand how can I implement the same functionality which provides navigation view in sencha touch 2, but ....
Each item of the 'Ext.NavigationView' component should have it's own unique set of 'navigationBar' elements. I mean set of buttons, for example.
I know that I can do something like this:
this.getMain().getNavigationBar().rightBox.removeAll();
this.getMain().getNavigationBar().rightBox.add(this.getSettingButton());
//where 'getSettingButton' predefined by me a button
And do this action each time when 'push' event happens (clear 'navigationBar' and add appropriate set of buttons)
Of course, I even can implement 'Ext.Panel' with 'layout: card' and set of 'Ext.panel' elements in the 'items' property, each of which will be have unique 'toolbar'.
To control the behavior I can use 'setActiveItem' method.
But, I think each of these approaches is a bit weird, isn't it?
I expected that would be much more natural approach to implement it.
Most likely I don't know what I need. Confirm my doubts. What is the best way to do it.
Currently, Ext.NavigationView tends to perform navigation between "simple" views. "Simple" here means that your views are just panel with innerHTML, not the "complicated" ones with functional buttons, toolbars, etc.
As far as I know, there're 2 ways you could try:
If you still want to use Ext.NavigationView, you can customize your NavigationBar with titles, items (buttons, spacers, etc.) as normal components through navigationBar config, getter and setter.
(recommended) If your views are completely different from each other, you should use many Ext.Container with different items of your choice (for eg. first container with simple HTML announcement, second one with some extra Ext.Button, and so on). Simple use animateActiveItem() for animated navigation. This way is much more flexible, I suppose.
I have seen that in Cocoa I can create a custom view using drawing primitives which allows me to draw what I like but at a very low level.
Instead I'd like to create custom widgets using a combination of existing controls. For example:
I'd like to create a table with images and combobox in cells
I'd like to create a custom widget wich is a combination of several (for example a list, a button and combobox)
How can I approach this problem ?
Secondly a typical cocoa developer uses external controls? Is there a repository or a list of interesting external custom controls (commercial or free) ?
I'd like to create a table with images and combobox in cells
There already exists NSImageCell and NSComboBoxCell. Are you sure you need to do anything different?
If the problem is that you want an image and a combo box in the same cell, you will have to subclass NSCell. Currently table views can only contain cells, not views, which makes your life harder (as understanding how cell drawing works is more difficult). That will change in Lion, however, so if you can wait until then, this will become easier!
I'd like to create a custom widget wich is a combination of several (for example a list, a button and combobox)
How is your custom widget different to just placing those three things in the same view?
You could write your own NSView subclass. When it's created, it should create a list, a button and a combobox and add them as subviews to itself. Your NSView subclass should handle the logic of keeping them in sync or doing whatever it is you want them to do. Then, to use this combination control in Interface Builder, you place a Custom View and set its class (rightmost tab of the inspector) to your NSView subclass.
BTW, on a tangent, are you sure you mean combobox? Loads of people coming from Windows get this one wrong. A combobox is a combination of a menu and a text field: it allows the user to enter custom text that is not in the menu. If you just want a dropdown menu of choices (and the user can't enter a custom one), you use an NSPopupButton.
Secondly a typical cocoa developer uses external controls?
Yes, sometimes. Things like BWToolkit can be very useful. There's a lot more that are just floating around mailing lists as code snippets, rather than being cleaned up and put in a library. Search for what you need to do!
I need to display a progress of loading of item's children. Please advise how to implement a progress indicator like it's done in Mail application:
(source: quicksnapper.com)
P. S. Here a source code of using indicator sub-views: http://snippets.dzone.com/posts/show/7684
This is harder than it should be, because Apple does not provide an NSProgressIndicatorCell. While table and outline views support the idea of custom cells being displayed within them, they are not set up to easily support custom subviews.
So the trick becomes, how do you get a a complete NSProgressIndicator view to display and animate at the desired spot in your window, without the ability to actually install it in the table view row?
The trick I've used is to literally install the NSProgressIndicator as a subview of the outline or table view itself. To find the location to add the subview, so it looks like it's "in the row", use the frameOfCellAtColumn:row: method. You can then position your progress indicator within that location of the outline view. When you're done spinning the progress indicator, you probably don't want to show it any more, so just remove it from its superview and discard it.
You will want to make sure you set the required autosizing flags on the progress indicator, so that it floats in the correct direction when/if your outline view is resized.
I'm sure there are other hacks like this to achieve the desired end result. I don't think there is any super-clean way to accomplish this trick.
Vienna is an open-source (Apache license) feed reader that has this in its source list. You should look at the Vienna source code to see how they did it.
Viena's implementation is not perfect. Add a feed to a folder then as it is loading and the progress indicator is busy collapse that folder. You will see the progress indicator still running in the same location.