Author: Luca Zanini

  • The Form Layout Column control of the Extension Library

    The Form Layout Column control allow you to place the various controls (such as Form Layout Row) on multiple columns. In the post The Form Table and Form Layout Row controls of the Extension Library I built a xpage with two Form Layout Row controls at different lines, using two Column Layout Form controls you…

  • Non-abundant sums

    From the Project Euler Problem 23: A perfect number is a number for which the sum of its proper divisors is exactly equal to the number. For example, the sum of the proper divisors of 28 would be 1 + 2 + 4 + 7 + 14 = 28, which means that 28 is a…

  • Updating frequently a TextView inside a loop

    The problem How to update a TextView inside a loop or, more generally, how to update frequently an UI element of an Activity.

  • ìNames scores

    From the Project Euler Problem 22: Using […] a 46K text file containing over five-thousand first names, begin by sorting it into alphabetical order. Then working out the alphabetical value for each name, multiply this value by its alphabetical position in the list to obtain a name score. For example, when the list is sorted…

  • The Form Table and Form Layout Row controls of the Extension Library

    The Form Table and Form Layout Row controls allow you to easily implement a form with the fields and their labels. In this post I use these two controls to convert the form “Document” to xpage in a database that inherits from the template Doc Library – Notes & web (8.5).

  • Amicable numbers

    From the Project Euler Problem 21: Let d(n) be defined as the sum of proper divisors of n (numbers less than n which divide evenly into n). If d(a) = b and d(b) = a, where a ≠ b, then a and b are an amicable pair and each of a and b are called…

  • Factorial digit sum

    From the Project Euler Problem 20: n! means n * (n – 1) * … * 3 * 2 * 1 For example, 10! = 10 * 9 … * 3 * 2 * 1 = 3628800, and the sum of the digits in the number 10! is 3 + 6 + 2 + 8…

  • The Exception Unable to instantiate activity ComponentInfo

    If you have this error “Unable to instantiate activity ComponentInfo” in the LogCat of Android just you launch your app, first you have to check the file AndroidManifest.xml especially the code lines package=”[your package]” it is an attribute of the tag manifest and you insert a unique name for your app in java package style,…

  • ActionBar, Fragment and screen rotation

    In the post Tab Layout in Android with ActionBar and Fragment as dnoray wrote in his comment, there is a problem: when you rotate the screen (ctrl + F11 in the emulator) there is an overlap of the two fragments as seen in the figure. For a further discussion on this topic you can read…

  • Counting Sundays

    From the Project Euler Problem 19: You are given the following information, but you may prefer to do some research for yourself. 1 Jan 1900 was a Monday. Thirty days has September, April, June and November. All the rest have thirty-one, Saving February alone, Which has twenty-eight, rain or shine. And on leap years, twenty-nine.…