reusability

I would like to add a collection of objects to an arrayList ,only if the particular attribute is not null. I am thinking of extending the ArrayList and implementing the check inside the child class. One alternate way is to check for the the attribute before putting it in a Arraylist, but that would mean , i will have to scatter the if checks every where if i need to add the objects to the arraylist based on the logic. I would like to know your thoughts on it ... on a second thought is it a overkill ? Tomasz Nurkiewicz Decorator pattern I would actually recommend wrapping ArrayList using well

I have a custom UITableViewCell which contains several UIButtons. Each button's frame position is relative to the cell width. I set autoresizingMask=UIViewAutoresizingFlexibleWidth so it will adjust the cell width and the button positions properly when the application starts with the device either in landscape or portrait mode. The issue is when the device is rotated from one mode to the other, the buttons do not adjust positions because the UITableViewCell is reusable. In other words, the cell is not initialized based on the new UITalbeView width because the cell's function initWithStyle is

I've got three different UITableViews, each in it's own view, accessed via tabs. All three tables would ideally share the same custom UITableViewCell class and .xib file. I started with one table, setting the class of the .xib to my custom class and the File's Owner of the .xib to the table's parent UIViewController, which works great. All of the custom view-related code is in the cell's class (background images based on a property set by the controller, custom cell height based on the number of lines a label requires based on a cell property set by the controller, etc.). The result is nice:

ViewHolder pattern improves ListView scrolling framerate, as seen in following example: https://developer.android.com/resources/samples/ApiDemos/src/com/example/android/apis/view/List14.html Is it possible to keep this pattern while using different kind of Views for different rows? In other words, is it possible to do something like: public View getView(int position, View view, ViewGroup parent) { // calculate viewID here if (view == null || *view is not null but was created from different XML than viewID* ) { view = mInflater.inflate(viewId, null); Yes, though it is far better to override

When using UITableView, we can reuse its cells using [[ UITableViewCell alloc] initWithStyle: reuseIdentifier:] and [uiTableViewInstance dequeueReusableCellWithIdentifier:] methods. This helps keep memory in check for huge tables as only a few cells are there in the view at a given instant. I want to create a UIScrollView that has many subviews. Inserting all the subviews takes up a lot of memory and initial time that I want to avoid. Does Apple API provides ways to reuse such custom components (a UIView or a subclass of it here) just like cell views using a identifier? I will create one if

I am trying to implement reusable charting with d3js, where chart type is changed based on user selection from drop-down menu. My code here: http://tributary.io/inlet/8085642 GOAL: redraw new chart type in place of old chart when user selects type from the drop down menu. I have everything set up as needed: can draw each chart on its own manually, the drop-down menu will console.log the name of the chart type I want to draw (line, area, candle), but obviously the goal is to do this programatically. EDIT: eliminated aside from below, not related to original question above. As Lars said, the

I'm constructing a UITableView with variable height custom table cells, their height determined by the size of a contained multi-line UILabel. I've got the tableView:heightForRowAtIndexPath: delegate method wired up and calculating the final height correctly using sizeWithFont:constrainedToSize: . I've run across strange issue: by the time the data source method tableView:cellForRowAtIndexPath: is called, the correct per-row height has already been determined as described above, but the frame of the cell does not match that height. Instead, the frame.size.height property of the cell is the