Java LayOut Tools B.N Veren Deepak

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Java LayOut Tools B.N Veren Deepak

• Flow Layout
• Border Layout
• Card Layout
• Grid Bag
• Grid

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GUI Designer should

• Know Users and their needs
• Prevent errors
• Make information readily available
• Optimise User abilities
• Consistent with placement of colour shemes and
  components

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LayOut Manager

• Is the Object that determines manner in which
  components are arranged in container
• Java standard Class libraries predefined Layout
  managers are
• Flow LayOut, Border, Card, Grid, GridBag Layout
  defined in the AWT.
• Order Layout in the Swing.
• Extended layouts are additional layout managers
  included with simplicity professional.

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Layout manager

• Each layout managers has own rules governing how
  the components will be arranged
• Some layout managers pay attention to a
• component's preferred size or alignment
• A layout manager attempts to vary layout as
  components are added and as containers are
  resized
• We can assign layout manager for a container
  however every container has a layout manger by
  default.

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Flow Layout

• Puts as many components possible on row and moves
  to next row
• Rows are created as needed to accomadate all of
  components
• Components are displayed order in which they are
  added to container

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Flow layout

• Each button is made large enough to accommodate
  its label
• Components can be left aligned, right aligned or
  centred.
• Horizontal and vertical lines can be explicitly
  set.

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Border Layout

• This layout can hold upto five parts arranged in
  north, south, east and west.
• Each area displays one component just as another
  container like Jpanel
• Each of four areas enlarges as components are
  added to it.
• Centre area expands to fill space as needed
• Nothing added to outer areas they take no space
  and others expand to fill gap void.
• Holds five empty spaces, when done with adding
  parts spaces can be deleted by unchecking show
  empty panels check box

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Grid layout

• Presents a containers components in rectangular
  grid of rows and columns.
• One component is placed in each cell of grid and
  all cells have same size.
• Size of each cell is determined by the overall
  size of container
• Components are added from top to bottom and left
  to right on each row.
• Grid layout hold rowscolumns empty spaces
• Remaining empty spaces are removed by unchecking
  show empty panels checkbox.
• Grid dimensions are diminished empty spaces are
  removed from bottom and right.
• Parts sitting in these spaces removed to
  Recycling bin

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Box layout

• Organises components either horizontally in one
  row or vertically in one column
• By combing multiple containers using box layout
  different configurations can be created
• New Boxlayout object must be created for each
  component
• Multiple containers with box layouts are often
  preferred to one container that uses more
  complicated Gridbag layout manager
• Components are placed top to bottom or left to
  right based on arrival
• To fill up space between components invisible
  components are added
• Rigid area is created using createRigidArea
  method of box class.
• Glue is created using createHorizontalGlue or
  create verticaGluemethods

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Grid bag Layout

• Most flexible and versatile among AWT layout
  managers.
• Once set of parts have been added user can
  specify set of constraints to be applied to each
  part and how parts should be laid out respect to
  each other
• Starts with single empty single space, user can
  add or remove empty spaces or change order of
  parts using properties.

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Grid bag layout contd..

• Grid bag constraints are
• 1. gridx, gridy The part's position in the grid.
• 2. width, height The number of rows and columns
  the part should occupy.
• 3.anchor A part can be anchored to any side of
  its cell. The user can choose a value by clicking
  the mouse in the grid in the appropriate table
  cell.
• 4. fill How the part should expand to fill extra
  space. The possible values are none, horizontal,
  vertical, and both. The user can cycle through
  these values by clicking the mouse on the
  appropriate table cell.
• 5. xweight, yweight Specifies how extra space
  should be distributed among parts.
• 6. x internal..., y internal... Internal padding
  of the part.
• 7. top inset, left inset, bottom inset, right
  inset External padding of the part.

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Extended Layouts

• Tabbed card layout
• Left side layout
• Right side layout
• Bottom layout
• Top layout
• Scroll panel layout
• Absolute layout