iTunes Navigation Header

If you are one of those people, who thinks swing is ugly, I suggest checking out, Exploding Pixels, blog of Ken Orr creator of macwidgets.

Two of his recent posts,

covers the process of recreating iTunes navigation header (seen in the iTunes music store - the black shiny bar at the top). I wanted to try it on a toy project of mine, following is a direct translation of his code to Clojure, for a detailed explanation of the code check his posts.

 (defn itunes-header [layout]
   (let [header-height 25
         ;the background colors used in the multi-stop gradient.
         background-color-1  (java.awt.Color. 0x393939)
         background-color-2  (java.awt.Color. 0x2e2e2e)
         background-color-3  (java.awt.Color. 0x232323)
         background-color-4  (java.awt.Color. 0x282828)
         ;the color to use for the top and bottom border.
         border-color  (java.awt.Color. 0x171717)
         ;the inner shadow colors on the top of the header.
         top-shadow-color-1  (java.awt.Color. 0x292929)
         top-shadow-color-2  (java.awt.Color. 0x353535)
         top-shadow-color-3  (java.awt.Color. 0x383838)
         ;the inner shadow colors on the bottom of the header.
         bottom-shadow-color-1  (java.awt.Color. 0x2c2c2c)
         bottom-shadow-color-2  (java.awt.Color. 0x363636)]

     (proxy [javax.swing.JPanel] [layout] 
       (getPreferredSize [] (java.awt.Dimension. -1 header-height))
       (paintComponent
        [g]
        (let [graphics (cast java.awt.Graphics2D (.create g))
              height   (.getHeight this)
              width    (.getWidth this)
              mid-y    (int (/ height 2))]
          (doto graphics
            ;paint the top half of the background with 
            ;the corresponding gradient
            (.setPaint  (java.awt.GradientPaint. 0 0 background-color-1 
                                                 0 mid-y background-color-2))
            (.fillRect 0 0 width mid-y)
            ;paint the top half of the background with 
            ;the corresponding gradient
            (.setPaint 
             (java.awt.GradientPaint. 0 (+ mid-y 1) background-color-3
                                      0 height background-color-4))
            (.fillRect 0 mid-y width height)
            ;draw the top inner shadow
            (.setColor top-shadow-color-1)
            (.drawLine 0 1 width 1)
            (.setColor top-shadow-color-2)
            (.drawLine 0 2 width 2)
            (.setColor top-shadow-color-3)
            (.drawLine 0 3 width 3)
            ;draw the bottom inner shadow.
            (.setColor bottom-shadow-color-1)
            (.drawLine 0 (- height 3) width (- height 3))
            (.setColor bottom-shadow-color-2)
            (.drawLine 0 (- height 2) width (- height 2))
            ;draw the top and bottom border
            (.setColor border-color)
            (.drawLine 0 0 width 0)
            (.drawLine 0 (- height 1) width (- height 1)))
          (.dispose graphics))))))

 (defn itunes-header-button-ui []
   (let [text-color         java.awt.Color/WHITE
         text-shadow-color  java.awt.Color/BLACK
         ;the gradient colors for when the button is selected.
         selected-background-color-1  (java.awt.Color. 0x141414)
         selected-background-color-2  (java.awt.Color. 0x1e1e1e)
         selected-background-color-3  (java.awt.Color. 0x191919)
         selected-background-color-4  (java.awt.Color. 0x1e1e1e)
         ;the border colors for the button.
         selected-top-border     (java.awt.Color. 0x030303)
         selected-bottom-border  (java.awt.Color. 0x292929)
         ;the border colors between buttons.
         left-border   (java.awt.Color. 255,255,255,21)
         right-border  (java.awt.Color. 0,0,0,125)
         selected-inner-shadow-color-1  (java.awt.Color. 0x161616)
         selected-inner-shadow-color-2  (java.awt.Color. 0x171717)
         selected-inner-shadow-color-3  (java.awt.Color. 0x191919)] 

     (proxy [javax.swing.plaf.basic.BasicButtonUI] [] 
       (installDefaults 
        [button]
        (proxy-super installDefaults button)
        (.setBackground button (java.awt.Color. 0 0 0 0))
        (.setOpaque button false))
         ;if the button is selected, paint the special background now.
         ;if it is not selected paint the left and right highlight border.
       (paint
        [graphics component]
        (let [button (cast javax.swing.AbstractButton component)] 
          (if (= (.isSelected button) true)
            (.paintButtonPressed this graphics button)
            (do
              (doto graphics
                (.setColor left-border)
                (.drawLine 0 1 0 (- (.getHeight button) 2))
                (.setColor right-border)
                (.drawLine 
                 (- (.getWidth button) 1) 1
                 (- (.getWidth button) 1) (- (.getHeight button) 2)))))
          (proxy-super paint graphics component)))
        ; we need to override the paintText method so that we can paint
        ; the text shadow. the paintText method in BasicButtonUI pulls
        ; the color to use from the foreground property -- there is no
        ; way to change this during the painting process without causing
        ; an infinite sequence of events, so we must implement our own
        ; text painting.      
       (paintText 
        [graphics button text-rect text]
        (let [font-metrics (.getFontMetrics graphics (.getFont button))
              mnemonix-index (.getDisplayedMnemonicIndex button)]
          ;paint the shadow text.
          (.setColor graphics text-shadow-color)
          (javax.swing.plaf.basic.BasicGraphicsUtils/drawStringUnderlineCharAt
           graphics text mnemonix-index 
           (+ (.x text-rect) (.getTextShiftOffset this))
           (+ (.y text-rect) 
              (.getAscent font-metrics) 
              (.getTextShiftOffset this) -1))
          ;paint the actual text.
          (.setColor graphics text-color)
          (javax.swing.plaf.basic.BasicGraphicsUtils/drawStringUnderlineCharAt
           graphics text mnemonix-index 
           (+ (.x text-rect) (.getTextShiftOffset this))
           (+ (.y text-rect) 
              (.getAscent font-metrics) 
              (.getTextShiftOffset this)))))
       ;Paints the selected buttons state, also used as the pressed state.
       (paintButtonPressed
        [g button]
        (let [height   (.getHeight button)
              width    (.getWidth button)
              mid-y    (int (/ height 2))
              graphics (cast java.awt.Graphics2D g)]
          (doto graphics
            (.setPaint 
             (java.awt.GradientPaint. 0 0 selected-background-color-1
                                      0 mid-y selected-background-color-2))
            (.fillRect 0 0 width mid-y)
            (.setPaint 
             (java.awt.GradientPaint. 
              0 (+ 1 mid-y) selected-background-color-3
              0 height selected-background-color-4))
            (.fillRect 0 mid-y width height)
            ;draw the top and bottom border.
            (.setColor selected-top-border)
            (.drawLine 0 0 width 0)
            (.setColor selected-bottom-border)
            (.drawLine 0 (- height 1) width (- height 1))
            ;paint the outter part of the inner shadow.
            (.setColor selected-inner-shadow-color-1)
            (.drawLine 0 1 0 (- height 2))
            (.drawLine 0 1 width 1)
            (.drawLine (- width 1) 1 (- width 1) (- height 2))
            ;paint the middle part of the inner shadow.
            (.setColor selected-inner-shadow-color-2)
            (.drawLine 1 1 1 (- height 2))
            (.drawLine 0 2 width 2)
            (.drawLine (- width 2) 1 (- width 2) (- height 2))
            ;paint the inner part of the inner shadow.
            (.setColor selected-inner-shadow-color-3)
            (.drawLine 2 1 2 (- height 2))
            (.drawLine 0 3 width 3)
            (.drawLine (- width 3) 1 (- width 3) (- height 2))))))))

Glue them together,

 (let [frame (javax.swing.JFrame. "This is a test")
       panel (javax.swing.JPanel. 
              (net.miginfocom.swing.MigLayout. "fillx" ""))
       header (itunes-header 
               (net.miginfocom.swing.MigLayout. "insets 0 0 0 0, gapx 0"))
       music   (javax.swing.JButton. "Music")
       movies  (javax.swing.JButton. "Movies")]

   (.setUI music (itunes-header-button-ui))
   (.setUI movies (itunes-header-button-ui))

   (.add header music )
   (.add header movies)
   (.add panel header "north")
   (doto frame
     (.add panel)
     (.setSize 400 150)
     (.setVisible true)))

Result is a very nice looking iTunes like header,

iTunes header