Class Panel

java.lang.Object
com.googlecode.lanterna.gui2.AbstractComponent<Panel>
com.googlecode.lanterna.gui2.Panel
All Implemented Interfaces:
Component, Container, TextGUIElement
Direct Known Subclasses:
SplitPanel
public class Panel extends AbstractComponent<Panel> implements Container
This class is the basic building block for creating user interfaces, being the standard implementation of Container that supports multiple children. A Panel is a component that can contain one or more other components, including nested panels. The panel itself doesn't have any particular appearance and isn't interactable by itself, although you can set a border for the panel and interactable components inside the panel will receive input focus as expected.

  • Field Details

  • Constructor Details

    • Panel

      public Panel()
      Default constructor, creates a new panel with no child components and by default set to a vertical LinearLayout layout manager.

    • Panel

      public Panel(LayoutManager layoutManager)

  • Method Details

    • addComponent

      public Panel addComponent(Component component)
      Adds a new child component to the panel. Where within the panel the child will be displayed is up to the layout manager assigned to this panel. If the component has already been added to another panel, it will first be removed from that panel before added to this one.
      Parameters:
      component - Child component to add to this panel
      Returns:
      Itself

    • addComponent

      public Panel addComponent(int index, Component component)
      Adds a new child component to the panel. Where within the panel the child will be displayed is up to the layout manager assigned to this panel. If the component has already been added to another panel, it will first be removed from that panel before added to this one.
      Parameters:
      index - At what index to add the component among the existing components
      component - Child component to add to this panel
      Returns:
      Itself

    • addComponent

      public Panel addComponent(Component component, LayoutData layoutData)
      This method is a shortcut for calling: 
          
    component.setLayoutData(layoutData);
    panel.addComponent(component);
      Parameters:
      component - Component to add to the panel
      layoutData - Layout data to assign to the component
      Returns:
      Itself

    • containsComponent

      public boolean containsComponent(Component component)
      Description copied from interface: Container
      Returns true if this container contains the supplied component either directly or indirectly through intermediate containers.
      Specified by:
      containsComponent in interface Container
      Parameters:
      component - Component to check if it's part of this container
      Returns:
      true if the component is inside this Container, otherwise false

    • removeComponent

      public boolean removeComponent(Component component)
      Description copied from interface: Container
      Removes the component from the container. This should remove the component from the Container's internal data structure as well as call the onRemoved(..) method on the component itself if it was found inside the container.
      Specified by:
      removeComponent in interface Container
      Parameters:
      component - Component to remove from the Container
      Returns:
      true if the component existed inside the container and was removed, false otherwise

    • removeAllComponents

      public Panel removeAllComponents()
      Removes all child components from this panel
      Returns:
      Itself

    • setLayoutManager

      public Panel setLayoutManager(LayoutManager layoutManager)
      Assigns a new layout manager to this panel, replacing the previous layout manager assigned. Please note that if the panel is not empty at the time you assign a new layout manager, the existing components might not show up where you expect them and their layout data property might need to be re-assigned.
      Parameters:
      layoutManager - New layout manager this panel should be using
      Returns:
      Itself

    • getFillColorOverride

      public TextColor getFillColorOverride()
      Returns the color used to override the default background color from the theme, if set. Otherwise null is returned and whatever theme is assigned will be used to derive the fill color.
      Returns:
      The color, if any, used to fill the panel's unused space instead of the theme's color

    • setFillColorOverride

      public void setFillColorOverride(TextColor fillColor)
      Sets an override color to be used instead of the theme's color for Panels when drawing unused space. If called with null, it will reset back to the theme's color.
      Parameters:
      fillColor - Color to draw the unused space with instead of what the theme definition says, no null to go back to the theme definition

    • getLayoutManager

      public LayoutManager getLayoutManager()
      Returns the layout manager assigned to this panel
      Returns:
      Layout manager assigned to this panel

    • getChildCount

      public int getChildCount()
      Description copied from interface: Container
      Returns the number of children this container currently has
      Specified by:
      getChildCount in interface Container
      Returns:
      Number of children currently in this container

    • getChildren

      public Collection<Component> getChildren()
      Description copied from interface: Container
      Returns collection that is to be considered a copy of the list of children contained inside of this object. Modifying this collection will not affect any internal state.

      This method isn't deprecated but it should have originally been defined as returning a List instead of a Collection. See getChildrenList for a method with this signature.

      Specified by:
      getChildren in interface Container
      Returns:
      Child-components inside of this Container
      See Also:

    • getChildrenList

      public List<Component> getChildrenList()
      Description copied from interface: Container
      Returns list that is to be considered a copy of the list of children inside of this container. Modifying this list will not affect any internal state. This method is essentially the same as getChildren but the returned collection is a list.
      Specified by:
      getChildrenList in interface Container
      Returns:
      Child-components inside of this Container
      See Also:

    • createDefaultRenderer

      protected ComponentRenderer<Panel> createDefaultRenderer()
      Description copied from class: AbstractComponent
      When you create a custom component, you need to implement this method and return a Renderer which is responsible for taking care of sizing the component, rendering it and choosing where to place the cursor (if Interactable). This value is intended to be overridden by custom themes.
      Specified by:
      createDefaultRenderer in class AbstractComponent<Panel>
      Returns:
      Renderer to use when sizing and drawing this component

    • calculatePreferredSize

      public TerminalSize calculatePreferredSize()
      Description copied from class: AbstractComponent
      Invokes the component renderer's size calculation logic and returns the result. This value represents the preferred size and isn't necessarily what it will eventually be assigned later on.
      Overrides:
      calculatePreferredSize in class AbstractComponent<Panel>
      Returns:
      Size that the component renderer believes the component should be

    • isInvalid

      public boolean isInvalid()
      Description copied from interface: TextGUIElement
      Checks if this element (or any of its child components, if any) has signaled that what it's currently displaying is out of date and needs re-drawing.
      Specified by:
      isInvalid in interface TextGUIElement
      Overrides:
      isInvalid in class AbstractComponent<Panel>
      Returns:
      true if the component is invalid and needs redrawing, false otherwise

    • nextFocus

      public Interactable nextFocus(Interactable fromThis)
      Description copied from interface: Container
      Given an interactable, find the next one in line to receive focus. If the interactable isn't inside this container, this method should return null.
      Specified by:
      nextFocus in interface Container
      Parameters:
      fromThis - Component from which to get the next interactable, or if null, pick the first available interactable
      Returns:
      The next interactable component, or null if there are no more interactables in the list

    • previousFocus

      public Interactable previousFocus(Interactable fromThis)
      Description copied from interface: Container
      Given an interactable, find the previous one in line to receive focus. If the interactable isn't inside this container, this method should return null.
      Specified by:
      previousFocus in interface Container
      Parameters:
      fromThis - Component from which to get the previous interactable, or if null, pick the last interactable in the list
      Returns:
      The previous interactable component, or null if there are no more interactables in the list

    • handleInput

      public boolean handleInput(KeyStroke key)
      Description copied from interface: Container
      If an interactable component inside this container received a keyboard event that wasn't handled, the GUI system will recursively send the event to each parent container to give each of them a chance to consume the event. Return false if the implementer doesn't care about this particular keystroke and it will be automatically sent up the hierarchy the to next container. If you return true, the event will stop here and won't be reported as unhandled.
      Specified by:
      handleInput in interface Container
      Parameters:
      key - Keystroke that was ignored by the interactable inside this container
      Returns:
      true if this event was handled by this container and shouldn't be processed anymore, false if the container didn't take any action on the event and want to pass it on

    • updateLookupMap

      public void updateLookupMap(InteractableLookupMap interactableLookupMap)
      Description copied from interface: Container
      Takes a lookup map and updates it with information about where all the interactables inside of this container are located.
      Specified by:
      updateLookupMap in interface Container
      Parameters:
      interactableLookupMap - Interactable map to update

    • invalidate

      public void invalidate()
      Description copied from interface: Component
      Marks the component as invalid and requiring to be re-drawn at next opportunity. Container components should take this as a hint to layout the child components again.
      Specified by:
      invalidate in interface Component
      Overrides:
      invalidate in class AbstractComponent<Panel>

    • layout

      private void layout(TerminalSize size)