Add more detailed tooltips to window widgets

src/MainWindow.vala

@@ -583,18 +583,25 @@ public class MainWindow : Gtk.Window {
 
 
  // Crypto selection
+ const string crypto_help =
+ "TWOFISH and AES256 are the strongest algorithms. AES has hardware "
+ + "acceleration support on most platforms and is probably fastest.\n"
+ + "OpenPGP compliant algorithms are IDEA, SAFER-SK128, 3DES, CAST5, "
+ + "BLOWFISH. Later versions include AES128, AES192, AES256, TWOFISH. "
+ + "Even later versions include CAMELLIA.\n"
+ + "3DES is required by all OpenPGP implementations.\n"
+ + "PGP until version 2.6 only supported IDEA.";
+
  crypto_label = new Gtk.Label("Encryption Cipher:");
- crypto_label.set_tooltip_text(
- "TWOFISH, AES256, and CAMELLIA256 are the strongest ciphers.");
+ crypto_label.set_tooltip_text(crypto_help);
  crypto_label.set_hexpand(false);
  crypto_label.set_vexpand(true);
  crypto_label.set_halign(Gtk.Align.END);
  crypto_label.set_valign(Gtk.Align.CENTER);
  main_grid.add(crypto_label);
 
  crypto_box = new Gtk.ComboBoxText();
- crypto_box.set_tooltip_text(
- "TWOFISH, AES256, and CAMELLIA256 are the strongest ciphers.");
+ crypto_box.set_tooltip_text(crypto_help);
  crypto_box.changed.connect(refresh_widgets);
  foreach (string algo in cipher_algos) {
  crypto_box.append_text(algo);
@@ -607,16 +614,23 @@ public class MainWindow : Gtk.Window {
 
 
  // Hash selection
+ const string hash_help =
+ "SHA512 is the strongest algorithm. SHA algorithms have hardware "
+ + "acceleration support and are probably fastest.\n"
+ + "OpenPGP compliant algorithms are MD2, MD5, RIPE-MD/160, SHA-1. "
+ + "Later versions include SHA224, SHA256, SHA384, SHA512.\n"
+ + "SHA1 is required by all OpenPGP implementations.";
+
  hash_label = new Gtk.Label("Hash Algorithm:");
- hash_label.set_tooltip_text("SHA512 is the strongest hash.");
+ hash_label.set_tooltip_text(hash_help);
  hash_label.set_hexpand(false);
  hash_label.set_vexpand(true);
  hash_label.set_halign(Gtk.Align.END);
  hash_label.set_valign(Gtk.Align.CENTER);
  main_grid.add(hash_label);
 
  hash_box = new Gtk.ComboBoxText();
- hash_box.set_tooltip_text("SHA512 is the strongest hash.");
+ hash_box.set_tooltip_text(hash_help);
  hash_box.changed.connect(refresh_widgets);
  foreach (string algo in digest_algos) {
  hash_box.append_text(algo);
@@ -629,18 +643,21 @@ public class MainWindow : Gtk.Window {
 
 
  // Hash strengthen button
+ const string hash_strengthen_help =
+ "Enabling causes gpg to improve s2k passphrase mangling by hashing "
+ + "65011712 times. This increases the security against dictionary "
+ + "attacks at the cost of encryption time.";
+
  hash_strengthen_label = new Gtk.Label("Hash Strengthen:");
- hash_strengthen_label.set_tooltip_text(
- "Strengthening increases security but increases encryption time");
+ hash_strengthen_label.set_tooltip_text(hash_strengthen_help);
  hash_strengthen_label.set_hexpand(false);
  hash_strengthen_label.set_vexpand(true);
  hash_strengthen_label.set_halign(Gtk.Align.END);
  hash_strengthen_label.set_valign(Gtk.Align.CENTER);
  main_grid.add(hash_strengthen_label);
 
  hash_strengthen_button = new Gtk.Switch();
- hash_strengthen_button.set_tooltip_text(
- "Strengthening increases security but increases encryption time");
+ hash_strengthen_button.set_tooltip_text(hash_strengthen_help);
  hash_strengthen_button.state_set.connect((b) => {
  refresh_widgets();
  return false;
@@ -656,14 +673,27 @@ public class MainWindow : Gtk.Window {
 
 
  // Compression button
+ const string compression_help =
+ "Enabling compression uses the zip algorithm since this is the "
+ + "only one that is compatible with PGP. Disabling will break PGP "
+ + "compatibility.\n"
+ + "Compressing increases entropy and can improve security of the "
+ + "encryption.\n"
+ + "Using compression on compressable content like text can "
+ + "significantly decrease file size. Using compression on "
+ + "uncompressable content like images may increase file size "
+ + "slightly.";
+
  compression_label = new Gtk.Label("Compress:");
+ compression_label.set_tooltip_text(compression_help);
  compression_label.set_hexpand(false);
  compression_label.set_vexpand(true);
  compression_label.set_halign(Gtk.Align.END);
  compression_label.set_valign(Gtk.Align.CENTER);
  main_grid.add(compression_label);
 
  compression_button = new Gtk.Switch();
+ compression_button.set_tooltip_text(compression_help);
  compression_button.state_set.connect((b) => {
  refresh_widgets();
  return false;
@@ -679,14 +709,21 @@ public class MainWindow : Gtk.Window {
 
 
  // Armored button
+ const string armored_help =
+ "Enabling causes output to be wrapped in ASCII armor. This "
+ + "significantly increases file size and is not recommended in "
+ + "most cases.";
+
  armored_label = new Gtk.Label("Armored Output:");
+ armored_label.set_tooltip_text(armored_help);
  armored_label.set_hexpand(false);
  armored_label.set_vexpand(true);
  armored_label.set_halign(Gtk.Align.END);
  armored_label.set_valign(Gtk.Align.CENTER);
  main_grid.add(armored_label);
 
  armored_button = new Gtk.Switch();
+ armored_button.set_tooltip_text(armored_help);
  armored_button.set_hexpand(false);
  armored_button.set_vexpand(true);
  armored_button.set_halign(Gtk.Align.END);