9-patch image

9-patches images

1) What is the 9-patch image?

The Ninth Patch class is permit to drawing a bitmap in nine sections. The four corners are unscaled ; the four edges are scaled in one axis, and middle are scaled in two axis, and the middle is scaled in both axes. Normally , the middle is transparent so that that the patch can provide a selection around the rectangle. Essentially, it allows the creation of custom graphics that will scale the way that you define, when content added within the image exceeds the normal bounds of the graphic.  

Here's a quick guide to create a Nine-patch graphic using the Draw 9-patch tool. You'll need the PNG image with which you'd like to create a NinePatch.

1.    From a terminal, launch the draw9patch application from your SDK /tools directory.

2.    Drag your PNG image into the Draw 9-patch window (or File > Open 9-patch... to locate the file). Your workspace will now open.

The left pane is your drawing area, in which you can edit the lines for the stretchable patches and content area. The right pane is the preview area, where you can preview your graphic when stretched.

3.    Click within the 1-pixel perimeter to draw the lines that define the stretchable patches and (optional) content area. Right-click (or hold Shift and click, on Mac) to erase previously drawn lines.

4.    When done, select File > Save 9-patch...

Your image will be saved with the .9.png file name.

           optional controls include 

• Zoom: Adjust the zoom level of the graphic in the drawing area.
• Patch scale: Adjust the scale of the images in the preview area.
• Show lock: Visualize the non-drawable area of the graphic on mouse-over.
• Show patches: Preview the stretchable patches in the drawing area (pink is a stretchable patch).
• Show content: Highlight the content area in the preview images (purple is the area in which content is allowed).
• Show bad patches: Adds a red border around patch areas that may produce artifacts in the graphic when stretched. Visual coherence of your stretched image will be maintained if you eliminate all bad patches.