Lambda Expressions
Lambda expressions or anonymous functions can be quite useful. For example using jQuery in JavaScript all the work gets done in anonymous functions unless you particularly want to extract them and give them names…
jQuery(document).ready(function($) {
// ...
// Process the start button
$("#start").click(function() {
question = 0;
$("#data").css("display", "none");
$(".intro").fadeOut(function() {
// Do stuff
});
// ...
});
});
In C++ the syntax is curious in that there are a pair of square brackets enclosing ‘captured’ variables…
Read more →Hiding Edit Button
My Diary and Notes apps have a floating button in the corner of the screen which is used to switch between editing markdown text and viewing the result. Although it is part of the android Material Design, this button has been the subject of several issues raised by users.
I have seen apps which hide this button on scrolling, and this was one of the suggestions by users. Getting this to work correctly turned out to be more complex than initially considered, requiring two boolean flags and a lambda expression.
Read more →Derive Edit Position from Markdown
I had a request to switch to the edit view from the markdown view at the double tap position in my Diary app. The app already has a gesture detector so I just had to add an onDoubleTap function.
To get the tap position in the markdown view it is necessary to compensate for the position of the view on the screen, scrolling, and the display density.
// onDoubleTap
@Override
public boolean onDoubleTap(MotionEvent e)
{
if (shown)
{
int[] l = new int[2];
markdownView.getLocationOnScreen(l);
// Get tap position
float y = e.getY() - l[1];
int scrollY = markdownView.getScrollY();
int contentHeight = markdownView.getContentHeight();
float density = getResources().getDisplayMetrics().density;
// Get markdown position
final float p = (y + scrollY) / (contentHeight * density);
The function to get the view location on screen is a bit arcane in that you must provide a two element array for the X and Y co-ordinates. The position as a proportion of the total length of the displayed markdown is calculated from the corrected Y position, the scroll position and the density.
Read more →Pi-hole Cloudflare, DNSCrypt, Unbound Setup
Pi-hole
I came across a reference to Pi-hole recently, so as my old pi has been gathering dust, I thought I would try it out. The pi already had Raspbian Stretch Lite installed, so I uninstalled some of the packages I had previously installed, and loaded Pi-Hole using the One-Step Automated Install.
The installation script asks a series of questions using text dialogs and produces a log as it goes.
pi@catherine:~ $ curl -sSL https://install.pi-hole.net | bash
stty: 'standard input': Inappropriate ioctl for device
[✗] Root user check
[i] Script called with non-root privileges
The Pi-hole requires elevated privileges to install and run
Please check the installer for any concerns regarding this requirement
Make sure to download this script from a trusted source
[✓] Sudo utility check
stty: 'standard input': Inappropriate ioctl for device
[✓] Root user check
[i] Existing PHP installation detected : PHP version 7.0.33-0+deb9u3
[✓] Disk space check
[✓] Update local cache of available packages
[✓] Checking apt-get for upgraded packages... up to date!
[i] Installer Dependency checks...
[✓] Checking for apt-utils
[✓] Checking for dialog
[✓] Checking for debconf
[✓] Checking for dhcpcd5
[✓] Checking for git
[✓] Checking for iproute2
[✓] Checking for whiptail
[i] Using interface: eth0
[i] Using Cloudflare
[i] Your static IPv4 address: 192.168.1.252
[i] Your static IPv4 gateway: 192.168.1.254
[✓] Set IP address to 192.168.1.252
You may need to restart after the install is complete
[i] IPv4 address: 192.168.1.252
[i] IPv6 address:
[i] Web Interface On
[i] Web Server On
[i] Logging On.
[✗] Check for existing repository in /etc/.pihole
[✓] Clone https://github.com/pi-hole/pi-hole.git into /etc/.pihole
[✗] Check for existing repository in /var/www/html/admin
[✓] Clone https://github.com/pi-hole/AdminLTE.git into /var/www/html/admin
[i] Main Dependency checks...
[✓] Checking for cron
[✓] Checking for curl
[✓] Checking for dnsutils
[✓] Checking for iputils-ping
[✓] Checking for lsof
[✓] Checking for netcat
[✓] Checking for psmisc
[✓] Checking for sudo
[✓] Checking for unzip
[✓] Checking for wget
[✓] Checking for idn2
[✓] Checking for sqlite3
[✓] Checking for libcap2-bin
[✓] Checking for dns-root-data
[✓] Checking for resolvconf
[✓] Checking for libcap2
[✓] Checking for lighttpd
[✓] Checking for php7.0-common
[✓] Checking for php7.0-cgi
[✓] Checking for php7.0-sqlite3
[✓] Enabling lighttpd service to start on reboot...
[i] FTL Checks...
[✓] Detected ARM-hf architecture (armv6l)
[i] Checking for existing FTL binary...
[✓] Downloading and Installing FTL
[✓] Creating user 'pihole'
[✓] Installing scripts from /etc/.pihole
[i] Installing configs from /etc/.pihole...
[i] Existing dnsmasq.conf found... it is not a Pi-hole file, leaving alone!
[✓] Copying 01-pihole.conf to /etc/dnsmasq.d/01-pihole.conf
[i] Installing blocking page...
[✓] Creating directory for blocking page, and copying files
[✗] Backing up index.lighttpd.html
No default index.lighttpd.html file found... not backing up
[✓] Installing sudoer file
[✓] Installing latest Cron script
[✓] Installing latest logrotate script
[i] Backing up /etc/dnsmasq.conf to /etc/dnsmasq.conf.old
[i] Skipping firewall configuration
[✓] man pages installed and database updated
[i] Testing if systemd-resolved is enabled
[i] Systemd-resolved is not enabled
[✓] Restarting lighttpd service...
[✓] Enabling lighttpd service to start on reboot...
[i] Restarting services...
[✓] Enabling pihole-FTL service to start on reboot...
[✓] Restarting pihole-FTL service...
[✓] Deleting existing list cache
[i] Pi-hole blocking is enabled
[i] Neutrino emissions detected...
[✓] Pulling blocklist source list into range
[i] Target: raw.githubusercontent.com (hosts)
[✓] Status: Retrieval successful
[i] Target: mirror1.malwaredomains.com (justdomains)
[✓] Status: Retrieval successful
[i] Target: sysctl.org (hosts)
[✓] Status: Retrieval successful
[i] Target: zeustracker.abuse.ch (blocklist.php?download=domainblocklist)
[✓] Status: Retrieval successful
[i] Target: s3.amazonaws.com (simple_tracking.txt)
[✓] Status: Retrieval successful
[i] Target: s3.amazonaws.com (simple_ad.txt)
[✓] Status: Retrieval successful
[i] Target: hosts-file.net (ad_servers.txt)
[✓] Status: Retrieval successful
[✓] Consolidating blocklists
[✓] Extracting domains from blocklists
[i] Number of domains being pulled in by gravity: 135697
[✓] Removing duplicate domains
[i] Number of unique domains trapped in the Event Horizon: 113438
[i] Nothing to whitelist!
[i] Number of regex filters: 0
[✓] Parsing domains into hosts format
[✓] Cleaning up stray matter
[✓] Force-reloading DNS service
[✓] DNS service is running
[i] Pi-hole blocking will be enabled
[i] Enabling blocking
[✓] Reloading DNS service
[✓] Pi-hole Enabled
[i] Web Interface password: ********
[i] This can be changed using 'pihole -a -p'
[i] View the web interface at http://pi.hole/admin or http://192.168.1.252/admin
[i] You may now configure your devices to use the Pi-hole as their DNS server
[i] Pi-hole DNS (IPv4): 192.168.1.252
[i] If you set a new IP address, please restart the server running the Pi-hole
[i] The install log is located at: /etc/pihole/install.log
Installation Complete!
My router uses the IP address 192.168.1.254 and allocates DHCP
IP addresses from 192.168.1.1 and does not allow DHCP
configuration. I opted to use the ethernet port and use IP address
192.168.1.252 and the Cloudflare DNS service. The router does allow
DNS configuration, so I changed the default DNS to 192.168.1.252 so
I don’t have to make any changes to DNS configuration elsewhere.
Source Code Syntax Highlighting
One of the enhancements suggested for my android editor is syntax highlighting. The libraries I have found, including the one used in this blog, parse the input and produce output in HTML, using styled spans. Emacs makes extensive use of regular expressions for highlighting.
HTML output is not very useful for a text editor. It could be used with Html.fromHtml() to produce styled text. This would then be loaded back into the editor all while the user is attempting to edit the text. I don’t think so. So I explored alternatives.
Read more →