Input Help¶

The MathletFactory contains a built-in support for an input help allowing users to enter numbers, function expressions and text in symbolic visualisations of MM-Objects in an efficient way. This help system is based on input hints (which are presented as buttons to the user) and allows to integrate the definitions of valid variables in function expressions as input hints.

Valid Variables¶

Function expressions may define valid variables for checking user input in symbolic function representations. This is done by registering a list of variable identifiers in an operation via the setValidVariables(String[] validVariables) method in the classes Operation and MOpNumber. An empty list means that no variables at all are allowed, a null list means that all variables are allowed.

Whenever the user enters a function expression containing a variable not contained in this list, an error tooltip will be shown and the symbolic visualisation will remain in editing mode.

Notes:

• MOpNumber's setUseVariables(boolean) method is based on this technique. Calling this method is equivalent to a null list for true arguments and to an empty list for false arguments of the setUseVariables(boolean) method.
• changes of the list of valid variables will only be transfered into the visualisation via the render() method.

Examples:

1. Registering a valid variable in a MMFunctionDefByOp object:

MMFunctionDefByOp f = ...
f.getOperation().setValidVariables(new String[] { "x_{n}" });

2. Registering a valid variable in a MMOpNumber object:

MMOpNumber n = ...
n.setValidVariables(new String[] { "alpha" });

Activation with Applet Parameters¶

The input help can be controlled globally for a mathlet with the following applet parameters:

• enableInputHelp: enables globally the input help for a mathlet when set to true; false will disable the input help (default value)
• embedInputHelp: embeds the input help directly into the mathlet when set to true (default value); false will cause the input hints to be shown in a distinct window *
• globalInputHints: defines a list of input hints used for symbolic visualisations for every MM-Object
• globalFunctionInputHints: defines a list of input hints used for all functions in a mathlet

• the input help will be disabled if the option embedInputHelp is set to false and the [[.:embedding_mode|embedding mode]] is set to applet (inline mode) due to focus issues with the Java plugin.

The following example shows how to activate the input help with [[..:extensions:runtime_properties|runtime properties]] inside the properties.xml file of a mathlet:

<mf:runtime-settings>
    <mf:property name="enableInputHelp" type="string" value="true"/>
</mf:runtime-settings>

Display Properties¶

Although the input hint are based on display properties, the developer will use the TextInputDisplayProperties rarely. The follwing circumstances may cause the direct usage of this class:

• input hints containing multiple variables and/or functions are desired
• the text/label/description of input hints should be changed
• input hints for variables should be available but no error checking for valid variables is desired
• global settings should be performed via Java code rather than applet parameters

The following static methods are available in TextInputDisplayProperties:

• setInputHintData(String inputHint, String text, String label, String description): sets the data for an input hint (see [[.:input_help#input_hint_data|Input Hint Data]])
• enableInputHelp(boolean): enables globally the input help; equivalent to the applet parameter enableInputHelp

The following instance methods are available in TextInputDisplayProperties:

• addInputHints(String[] inputHints): registers the given list of input hints
• setUseValidVariables(boolean): sets whether valid variables from operations should be used as input hints

Examples:

1. Define an input hint which should not be treated as valid variable:

MMFunctionDefByOp f = ...
TextInputDisplayProperties inputProps = new TextInputDisplayProperties();
inputProps.addInputHints(new String[] { "x_{n}" });
f.getDisplayProperties().copyPropertiesFrom(inputProps);

2. Define a valid variable which should not be used as input hint:

MMFunctionDefByOp f = ...
f.getOperation().setValidVariables(new String[] { "x_{n}" });
TextInputDisplayProperties inputProps = new TextInputDisplayProperties();
inputProps.setUseValidVariables(false);
f.getDisplayProperties().copyPropertiesFrom(inputProps);

3. Change the text, label and description for the input hint x:

TextInputDisplayProperties.setInputHintData("x", "x", "x", "My Special Variable");

Input Hint Data¶

Every input hint is referenced by an unique name/identifier/key. It has the following properties:

• text: the text to be inserted into the textfield
• label: the text to be displayed on the button (may contain TeX commands)
• description: the text to be displayed in a tooltip (must NOT contain TeX; HTML is allowed)

Predefined Input Hints¶

Small Greek letters: alpha, beta, gamma, delta, epsilon, zeta, eta, theta, iota, kappa, lambda, mu, nu, xi, omicron, pi, rho, sigma, tau, upsilon, phi, chi, psi, omega

Big Greek letters: ALPHA, BETA, ...

Name	Description		+	Insert plus sign
-	Insert minus sign
*	Insert multiplication sign
/	Insert division sign
.	Insert decimal sign
,	Insert decimal sign
i	Insert imaginary number
infinity	Insert infinity
sqrt	Insert square root
^	Insert superscript
_	Insert index
abs	Insert absolute value
fac	Insert factorial sign
conj	Insert complex conjugated
cbrt	Insert cubic root
sign	Insert signum function
re	Insert real part function
im	Insert imaginary part function
ln	Insert logarithmus naturalis
log	Insert logarithmus naturalis
exp	Insert exponential function
cos	Insert cosine function
cosh	Insert hyperbolic cosine function
acos	Insert inverse cosine function
acosh	Insert inverse hyperbolic cosine function
sin	Insert sine function
sinh	Insert hyperbolic sine function
asin	Insert inverse sine function
asinh	Insert inverse hyperbolic sine function
tan	Insert tangent function
tanh	Insert hyperbolic tangent function
atan	Insert inverse tangent function
atanh	Insert inverse hyperbolic tangent function
cot	Insert cotangent function
coth	Insert hyperbolic cotangent function
acot	Insert inverse cotangent function
acoth	Insert inverse hyperbolic cotangent function