--- /dev/null
+[[visually-distinguish-primary-actions]]
+Visually distinguish primary actions
+------------------------------------
+
+Most forms and dialogs have at least two actions that can be performed,
+such as _Submit/Cancel_, _Save/Revert_ or _Yes/No_. Quite often, there
+are more, such as a login form with the actions _“Sign in”_,
+_“Register”_, and _“Forgot password”_. Usually, one of these actions is
+by far the most commonly used, and as such, the most likely one the user
+is going to be looking for.
+
+If all actions are represented by identical buttons (save for the
+caption), identifying the primary button can be quite slow, and the risk
+of selecting the wrong action by mistake (especially when in a hurry) is
+substantial:
+
+image:img/sign%20in%20-%20no%20distinction.png[Sign in - no distinction]
+
+By visually distinguishing primary actions, e.g. by color, size or
+shape, the user can quickly and accurately find them even in a crowded,
+cluttered UI. A typical approach is to use a stronger (more saturated)
+color with greater contrast for the primary actions, and a grayer, lower
+contrast color for the secondary actions:
+
+image:img/sign%20in%20-%20primary%20distinguished.png[Sign in - distinguished]
+
+Sometimes a view can have more than one primary action simultaneously
+available, although usually in different parts of the view. Google
+handles this quite elegantly by systematically styling _creation_
+primary buttons (such as _Compose_ in Gmail and _Create_ in Drive) in
+*red*, and other primary buttons (such as search) in *blue*, while
+leaving secondary buttons *gray*:
+
+image:img/google%20drive.png[Google drive]
+
+Choose colors wisely, though – red, for instance, means _“no”_, _"stop"_
+or _“danger”_ in most cultures, so using that for _“Yes”_ or _“Submit”_
+might send the user mixed signals. You might also want to take into
+account the effects of color blindness (affecting approximately 10% of
+men and 1% of women), especially if your user base is going to be tens
+of thousands of people.
+
+Setting a different visual style for primary action buttons is very easy
+to do in Vaadin by using the *BUTTON_DEFAULT* stylename in any of the
+built-in themes like Reindeer or Chameleon:
+
+[source,java]
+....
+Button btnSignIn = new Button("Sign in");
+btnSignIn.addStyleName(Reindeer.BUTTON_DEFAULT);
+....
+
+Another common approach, mainly used on the web, is to use text links
+instead of buttons for secondary or tertiary actions. This has a
+significantly stronger effect than color or size, and should only be
+used for significantly less common actions, such as a password reset
+request, not for the _“No”_ option in a _Yes/No_ dialog, for instance:
+
+image:img/sign%20in%20-%20all%20different.png[Sign in - all different]
+
+This is just as easy in Vaadin. Just use the *BUTTON_LINK* stylename
+defined in the base theme (and inherited in all built in themes), and
+your Button will look like a normal text-hyperlink.
+
+[source,java]
+....
+Button btnForgotPwd = new Button("Forgot password?");
+btnForgotPwd.addStyleName(Reindeer.BUTTON_LINK);
+....
+
+(Note that the separate *Link* component should not be used for server
+actions, since you can't bind a ClickListener to a Link.)
+
+[[consider-binding-the-enter-key-to-the-primary-action]]
+Consider binding the Enter key to the primary action
+++++++++++++++++++++++++++++++++++++++++++++++++++++
+
+Especially in short, often used forms, such as a login form, it is
+usually a good idea to bind the Enter key to the primary action. This
+relieves the user from having to move his hand from the keyboard to the
+mouse.
+
+[source,java]
+....
+Button btnSignIn = new Button("Sign in");
+btnSignIn.addStyleName(Reindeer.BUTTON_DEFAULT);
+btnSignIn.setClickShortcut(KeyCode.ENTER);
+....
+
+If the primary action is something that really mustn’t be invoked by
+mistake or without properly thinking about it first, however, it’s
+probably better not to bind it to a keyboard shortcut, to avoid
+accidental invocations. Another reason to abstain from a keyboard
+shortcut is if the form contains an input field in which Enter can be
+used for something, such as a multi-line text area (where Enter creates
+a line break).
projects / vaadin-framework.git / commitdiff
