Improving heavy layout's loading time - performance

I have an app which has quite a lot of activities, and all of the activities' layout have lots of views (TextViews, to display different kind of data in different styles, ImageViews etc).
When the activities load, they take too much time to load the layout/UI (more than a second).
Ques: Is there a way to reduce the time it takes to load the activity, because the activity takes too long to load the UI?
A short description of what I have:
All the layouts have at least 30-35 views
I am using Relative Layout
I am not nesting layouts, most of the views are parallel to each other, and the overdraw is at max 2x
All of the text views are custom, setting a custom font for them
The UI is being loaded in onCreate() of the activity
I am thinking of doing either of the following things:
Converting the app into Fragments in a way there are less number of activities, and more number of fragments. For example, there is one Home Activity which loads the first fragment, and further interactions with the app keep loading/switching between fragments for different purposes via Fragment Transactions. I would spawn a new activity only when I am hitting a limitation of Fragments.
Will it help improve the speed?
Disintegrate the UI in a way were the most basic UI is loaded in the view once the activity starts, and all the other UI elements are inflated in a background thread (AsyncTask) and are then added to the root of the current view.
In different opinions, which approach would be better?
Is there a better or standard way of solving this problem?
Appreciating all the inputs. Thanks in advance!

Here are some more suggestions to what you've already going to do.
If you inject views in onCreate() method, make sure you use design-time injection frameworks (Bufferknife or AndroidAnnotations) and not runtime ones (Guice, RoboGuice). Runtime frameworks definitely slow startup time down.
If you have views, which are not visible to the user initially, you can use ViewStub and load them on demand.

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The screens can be templates which will render differently based on the data loaded each time. Say I may have 30 types of different templates and each one need the API data for rendering the layout. The total 300 screens are a kind of repeating templates from the 30 different types. This is an app something based on e-learning platform.
Appreciate your suggestions in advance

Dynamically loading XAML Controls is slow?

I'm creating dynamic controls (buttons, scroll viewers, etc.) via Code Behind. I have a lot of processing done here (a lot of ViewModels processed, and what goes into each of the button), and I notice that every time I dynamically load the controls, it seems to be slow.
Is there any way to improve the performance so lower spec computers can better handle it?
Thank you

Optimize UI layers in a listview (+screenshots)

I'm analyzing my approach with Gmail's android developer's team approach in order to optimize drawing times and generally create more efficient apps.
My approach:
Below is the hierarchy inside a listview. It's quite straightforward. ExpandableListContentItem extends a Relative layout which has 3 Views:
Gmail app:
The following screenshot is how the listview in Gmail app works (SwipableListView). It's interesting to see that there is only one View (I guess aY extends ConvertationItemView) which in reality is quite more complicated than mine (I see 3 texts, 1 photo, 1 icon/button).
Question:
I would assume that this is a more lightweight approach to get rendered, is it so? Even if it takes me more time to code an optimal single customview per listview item it is worth the performance that it offers?
Finally the only way I know so far is to inflate an existing view inside another which is basically the first approach. I guess now my challenge would be to combine that relativeLayout with the 3 nested views into one. Is that correct?
PS:examples, open source code are welcome.
I would assume that this is a more lightweight approach to get rendered, is it so?
Yes it is. When you consider hierarchy, every parent measures their dimensions and passes it to child views from top to bottom. Reducing layers and having more flat view will save time.
Even if it takes me more time to code an optimal single customview per listview item it is worth the performance that it offers?
Depends on application you are developing. Depends on number of items in a list and how you get them. When you scroll through the list, if you think it is slow you might want to try that approach. I tried it on my previous applications and I could see the difference.
I guess now my challenge would be to combine that relativeLayout with the 3 nested views into one.
I don't know what you mean by combining them but the way Gmail does it that they have their Custom View. You can create your custom view.
Besides that, another thing to consider is overdraw. It is as important as having flat views. If you activate GPU Overdraw from developer tools and look at Gmail app row, you will see 0 overdraw. Make sure your code has no overdraw.
For further reading I would recommend you to check these blogs :
Performance Tuning On Android
Android Performance Case Study

How to approach game level switching

What is the best approach to switch to different scenes/areas in a 3D game from the render area?
Say you have a character and he moves into a new area, how would you go about unloading the area and loading the new area. Would you just load the render function up with different loading calls and only load them if they fell within certain parameters or would you create enumerators for each area and use something like a switch statement to switch to the new area after unloading your data for the current area?
I have always created REALLY bad transitions on small games I have made for a hobby and it usually kills my performance at some point or time.
Using enum or/and switch/case is not very flexible.
You can simply use a function, example load_area(i), to unload a previous level/area then load level i instead (it could use a smart resource manager as suggested by
Andon M. Coleman).
You should separate the resource handling from the game logic and the engine. Example, the rendering system should display currently loaded drawable resources rather than looping through enums and select which scene to render.
You should minimize the unloading/loading phases; depending on the game, you can completely avoid discrete transitions by using an LOD-like (level of detail) manager that updates resources dynamically depending on the current state of the game.

GWT List Grid performance

I have a gwt list grid which i need to show more than 1000 messages.
But it takes 40millsec to display each message. So it is very slow.
Can u help me so that i can show all messages in less time.
Thanks Nagaraju
As Bogdan said paging is your best bet.
However if your requirement strictly needs you to have the 1000+ lines at one time I would reconsider the grid approach.
When you are working with such a large amount of elements an iterative dom "touch" will be dirt slow.
See if you can rather create a component that gets the messages into String form with their markup. Then set the inner HTML once. You can then use something like jquery or gwtquery to attach handlers to the elements in a timely fashion.
Failing that you could use a lazy render method where you render only whats on-screen but that gets much more complicated.
Answering this 2 Year old question Just for Kicks -
GWT has progressed a lot since 2 Years.
GWT provides hell lot of options to User to do performance tuning.
GWT as done a lot of perormance tuning on widgets. GWT 2.5 has Cell
Widgets like CellList/CellTable/DataGrid which make displaying large
data easier , faster and with light weight heavy DOM.
Reference -
https://developers.google.com/web-toolkit/doc/latest/DevGuideUiCellWidgets
Summary -
Cell widgets (data presentation widgets) are high-performance, lightweight widgets composed of Cells for displaying data. Examples are lists, tables, trees and browsers. These widgets are designed to handle and display very large sets of data quickly. A cell widget renders its user interface as an HTML string, using innerHTML instead of traditional DOM manipulation. This design follows the flyweight pattern where data is accessed and cached only as needed, and passed to flyweight Cell objects. A cell widget can accept data from any type of data source. The data model handles asynchronous updates as well as push updates. When you change the data, the view is automatically updated.
In addition, cells can override onBrowserEvent to act as a flyweight that handles events that are fired on elements that were rendered by the cell.
Note -
1) CellTable being capable of displaying large data also come with Pager options and also AutoPage on Scrolling option ( example CellList )
2) Also, if you come across any other performance issues in GWT you can call in the Bazooka features of GWT - SpeedTracer, Logging, Chrome Dev tools Profiling, GWT Light Weight Metrics, Code Splitting, GWT Compiler Metrics, GWT Closure Compiler, Resource Bundling to crush it !!!!
1000 items for a web-based application is too much. Try implementing some sort of paging algorithm. You could look at the PagingScrollTable from gwt incubator ;)

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