Apple Gauge Control

Using XCode v3.1, Objective C/C++ and the rich graphic and animation (OpenGL, Quartz, Images, etc.) capabilities of Mac OS X, create one or more linear gauges/views for use in other XCode projects. Ideally, such modules could be used in either Mac OS X or iPhone software. The linear gauges will be used to display volume readings and/or percent of scale readings from external data sources. In actual use, the gauge may be required to render at least once a second to data value changes. ## Deliverables # Display Properties The properties discussed in this section might be described as display characteristics for linear gauges. The previous section listed general properties every linear gauge should possess; many of the properties listed below could easily be applied to any style of linear gauge. ·? ? ? ? ? ? ? ? **Major Tick Color** The color value used when rendering the *Major Ticks* of a linear gauge; default color is black. ·? ? ? ? ? ? ? ? **Minor Tick Color** A color value used when rendering the *Minor Ticks* of a linear gauge; default color is black. ·? ? ? ? ? ? ? ? **Scale Color** The color value used when rendering the numeric scale of the linear; default color is black. ·? ? ? ? ? ? ? ? **Scale Font** The font name, size, and style (bold or italic) for rendering the numeric scale; defaults should be the system default font. ·? ? ? ? ? ? ? ? **Level Indicator Color** The color value used when rendering the level indication for the gauge’s *Value* property; default color is solid red. ·? ? ? ? ? ? ? ? **Level Indicator Style** *Flat Solid*: the indicator drawing is a simple 2-D drawing with a solid color fill. *Flat Gradient*: the indicator is a simple 2-D drawing with a gradient color fill. This style will require two color choices and a direction for the gradient fill. *3D Solid*: an indicator style that appears as a tube of liquid, rendered with appropriate shadow effects and filled with a solid color fill. *3D Gradient*: an indicator style similar to *3D Solid* except the color fill for the level tube is a gradient. This property will require two color choices and a direction for the gradient fill. ·? ? ? ? ? ? ? ? **Background Margin** A numeric value in pixels that describes a rectangular area around the gauge’s bounding rectangle; the number represents a value from zero (indicating no margin) to a value in pixels that becomes a constant border around the gauge. For example, a *Background Margin* of 4 defines a rectangular region, 4 pixels outside the bounding box of the gauge; the gauge resides in an area centered within the background with 4 pixels above, below, left and right of the gauge. The margin value defaults to zero. ·? ? ? ? ? ? ? ? **Background Style** The type of background enhancement applied to the gauge’s bounding rectangle. *Transparent*: the background is transparent allowing the parent view to show through; this is the default. *Color*: a solid color chosen which becomes the background for the gauge. *Gradient*: two colors chosen and direction for a gradient pattern to render as the background of the gauge. *Image:* an image file to use for the background of the gauge. Many of the aforementioned display characteristics will be required during rendering for any “kind?? of linear gauge. The purpose in devoting a separate discussion of these items is so that these will be exposed programmatically like the *General Properties* as property “getters?? and “setters??. # Linear Gauge Samples Below are samples of some linear gauges. These samples are provided as a guide to the types of effects and the appearance desired in the Apple linear gauge. ## *Simple Linear * ****See attached "Simple [login to view URL]" The above sample is a relatively simple linear; however, this gauge does include many of the “wish list?? properties discussed in the previous section such as the background margin, background style, and scale font. ## *Advanced Linear* ****See attached "Advanced [login to view URL]" The above linear gauge is a scaled value linear with some interesting properties. The background, while not symmetrical, as described in *Background Margin*, does display an image for a nice bordered effect to the gauge. Unlike the simpler example, this image employs different colors for the level indication, scale, major ticks and minor ticks. ## *Specialized Linear* ****See attached "Specialized [login to view URL]" The thermometer image above is included as a *specialized* linear. Common properties with other linear gauges include a display style of “actual scale??, major & minor tick marks, scale numbers, a level indication, and a background margin and style. Of course, the differences in the above image are the dual scale, embedded labels (degrees C and F), and the level indicator having a bulb at the bottom.