Struct gtk4::Constraint[][src]

pub struct Constraint(_);
Expand description

Constraint describes a constraint between attributes of two widgets, expressed as a linear equation.

The typical equation for a constraint is:

  target.target_attr = source.source_attr × multiplier + constant

Each Constraint is part of a system that will be solved by a ConstraintLayout in order to allocate and position each child widget or guide.

The source and target, as well as their attributes, of a Constraint instance are immutable after creation.

Implements

glib::ObjectExt

Implementations

Creates a new constraint representing a relation between a layout attribute on a source and a layout attribute on a target.

target

the target of the constraint

target_attribute

the attribute of target to be set

relation

the relation equivalence between target_attribute and source_attribute

source

the source of the constraint

source_attribute

the attribute of source to be read

multiplier

a multiplication factor to be applied to source_attribute

constant

a constant factor to be added to source_attribute

strength

the strength of the constraint

Returns

the newly created constraint

Creates a new constraint representing a relation between a layout attribute on a target and a constant value.

target

a the target of the constraint

target_attribute

the attribute of target to be set

relation

the relation equivalence between target_attribute and constant

constant

a constant factor to be set on target_attribute

strength

the strength of the constraint

Returns

the newly created constraint

Creates a new builder-pattern struct instance to construct Constraint objects.

This method returns an instance of ConstraintBuilder which can be used to create Constraint objects.

Retrieves the constant factor added to the source attributes’ value.

Returns

a constant factor

Retrieves the multiplication factor applied to the source attribute’s value.

Returns

a multiplication factor

The order relation between the terms of the constraint.

Returns

a relation type

Retrieves the ConstraintTarget used as the source for the constraint.

If the source is set to NULL at creation, the constraint will use the widget using the ConstraintLayout as the source.

Returns

the source of the constraint

Retrieves the attribute of the source to be read by the constraint.

Returns

the source’s attribute

Retrieves the strength of the constraint.

Returns

the strength value

Retrieves the ConstraintTarget used as the target for the constraint.

If the targe is set to NULL at creation, the constraint will use the widget using the ConstraintLayout as the target.

Returns

a ConstraintTarget

Retrieves the attribute of the target to be set by the constraint.

Returns

the target’s attribute

Checks whether the constraint is attached to a ConstraintLayout, and it is contributing to the layout.

Returns

TRUE if the constraint is attached

Checks whether the constraint describes a relation between an attribute on the property::Constraint::target and a constant value.

Returns

TRUE if the constraint is a constant relation

Checks whether the constraint is a required relation for solving the constraint layout.

Returns

true if the constraint is required

Trait Implementations

Returns a copy of the value. Read more

Performs copy-assignment from source. Read more

Formats the value using the given formatter. Read more

Formats the value using the given formatter. Read more

Feeds this value into the given Hasher. Read more

Feeds a slice of this type into the given Hasher. Read more

This method returns an Ordering between self and other. Read more

Compares and returns the maximum of two values. Read more

Compares and returns the minimum of two values. Read more

Restrict a value to a certain interval. Read more

This method tests for self and other values to be equal, and is used by ==. Read more

This method tests for !=.

This method returns an ordering between self and other values if one exists. Read more

This method tests less than (for self and other) and is used by the < operator. Read more

This method tests less than or equal to (for self and other) and is used by the <= operator. Read more

This method tests greater than (for self and other) and is used by the > operator. Read more

This method tests greater than or equal to (for self and other) and is used by the >= operator. Read more

Returns the type identifier of Self.

Auto Trait Implementations

Blanket Implementations

Gets the TypeId of self. Read more

Immutably borrows from an owned value. Read more

Mutably borrows from an owned value. Read more

Upcasts an object to a superclass or interface T. Read more

Upcasts an object to a reference of its superclass or interface T. Read more

Tries to downcast to a subclass or interface implementor T. Read more

Tries to downcast to a reference of its subclass or interface implementor T. Read more

Tries to cast to an object of type T. This handles upcasting, downcasting and casting between interface and interface implementors. All checks are performed at runtime, while downcast and upcast will do many checks at compile-time already. Read more

Tries to cast to reference to an object of type T. This handles upcasting, downcasting and casting between interface and interface implementors. All checks are performed at runtime, while downcast and upcast will do many checks at compile-time already. Read more

Casts to T unconditionally. Read more

Casts to &T unconditionally. Read more

Performs the conversion.

Performs the conversion.

Returns true if the object is an instance of (can be cast to) T.

Safety Read more

Safety Read more

Safety Read more

Safety Read more

Safety Read more

Safety Read more

Same as connect but takes a SignalId instead of a signal name.

Same as connect_local but takes a SignalId instead of a signal name.

Same as connect_unsafe but takes a SignalId instead of a signal name.

Emit signal by signal id.

Same as emit but takes Value for the arguments.

Emit signal by its name.

Same as emit_by_name but takes Value for the arguments.

Emit signal with details by signal id.

Same as emit_with_details but takes Value for the arguments.

The resulting type after obtaining ownership.

Creates owned data from borrowed data, usually by cloning. Read more

🔬 This is a nightly-only experimental API. (toowned_clone_into)

recently added

Uses borrowed data to replace owned data, usually by cloning. Read more

Returns a SendValue clone of self.

Converts the given value to a String. Read more

The type returned in the event of a conversion error.

Performs the conversion.

The type returned in the event of a conversion error.

Performs the conversion.