When we create a new app in the DecSoft App Builder's IDE, the default app's designtime size is 320x480, and, there must be a reason to be like that, right? The reason is how DecSoft App Builder can, optionally, auto scale our apps. DecSoft App Builder can auto scale our apps, and, this works from smaller to larger logical resolutions, but (and this is what matter here) not at the contrary.
In other words, if we design our app in a 320x480 logical resolution, that app can automatically scaled and looks fine not only in devices with that logical resolution, but, also in larger logical resolutions, like 360x640 and so on. If, on the contrary, we design our app in a 360x640 logical resolution, the app can't scale down to smaller logical resolutions like 320x480.
The above image shown the Calculator sample app auto scale to larger logical resolution from their designtime original logical resolution of 320x480. In fact, and, as you can see, the Calculator sample do another thing: limit the scale to certain specific size, that is, instead of let the auto scale option to scale all the time, we limit the scale to certain specific size for larger logical resolutions.
Auto scale is optional
The auto scale of our app is optional; our app can have a fixed size, and, we can also change to the "scale" or "fixed" styles in runtime. What option we choose depend on the app that we plain to be developed. Probably the best (thinking to reach almost all the logical resolutions, from mobiles to larger screens) is to design our app with a logical resolution of 320x480, and then use the auto scale option, and then, like in the Calculator sample, fix the size of the app upon reach a more or less larger logical resolution.
Maybe a logical resolution of 320x480 for design time can appear very small. Well. You can see above the Calculator sample, which uses that logical resolution, and, works like we expected. Sometimes we can be tempted to use too much controls in one app's view: but there is no limit of app's views, so we can divide the views in various of them, if we need. The point is that, if we wanted that our app works from smaller to larger screens, our app designtime must be capable to run in the smaller screen that we consider.
Maybe our app is not planned to be deployed in mobile devices, so our designtime logical resolution can be greater. Maybe we no need to use the auto scale option, and we want that our app works always at certain logical resolution, because we perfectly know the devices in which the app works. Etcetera. Etcetera.
To finalize this blog entry, I want to note that, the default 320x480 logical resolution, are intended allows our app to works in devices like iPhone 4, for example. These days maybe we can design our apps in a more larger logical resolution like 360x640. Just remember that the auto scale option works from smaller to larger sizes, but not at the contrary, in other words, if you choose a logical resolution like 360x640, then the app can't be auto scaled into a 320x480 logical resolution.