This might help, from the list archives:
>>At 2:00 PM -0700 10/20/98, Jeff Davey wrote:
>>Does anyone know if there is a way to call battery image that appears on
>>the top of all the [Application] forms? I found the APIs to get battery
>>status and such, but it would be nice to put the bitmap in an application.
>
>Bitmap?? Ain't no bitmap, it's all just 'drawn', based on a gadget. A
bitmap would probably save a bunch of lines of code though.
>
>--Bob
>
>P.S. Here's a 'template' for the function, to get you started. :)
>
>static void DisplayBatteryLevel (FormPtr formP)
>{
> RectangleType r;
> RectangleType gaugeMainR;
> RectangleType gaugeEndR;
> Word frameEndWidth;
> Word frameEndHeight;
> Word batteryGaugeWidth;
> Word batteryPowerWidth;
> Word batteryGaugeMainWidth;
> Word batteryGaugeEndWidth;
> Short x1, x2, y1, y2;
> Byte batteryPercent;
>
> // Now fill in how much of the battery is left
> SysBatteryInfo(false, 0, 0, 0, 0, 0, &batteryPercent);
>
> // If percent is same as old, do nothing
> if (batteryPercent == LastKnownBatteryPercent)
> return;
>
> // Save new battery percent
> LastKnownBatteryPercent = batteryPercent;
>
> // Get the bounds of the battery gadget.
> formP = FrmGetActiveForm();
> FrmGetObjectBounds (formP, FrmGetObjectIndex (formP,
BatteryTestMainBatteryGadget), &r);
>
> frameEndHeight = r.extent.y / 4;
> frameEndWidth = frameEndHeight;
> batteryGaugeWidth = r.extent.x - frameEndWidth - 3;
>
> // Draw the frame of the battery gadget.
> x1 = r.topLeft.x;
> y1 = r.topLeft.y;
> x2 = x1 + r.extent.x - frameEndWidth - 2;
> y2 = y1 + r.extent.y - 1;
> WinDrawLine (x1, y1, x1, y2); // left side
> WinDrawLine (x1, y1, x2, y1); // top side
> WinDrawLine (x1, y2, x2, y2); // bottom side
> WinDrawLine (x2, y1, x2, y1 + frameEndHeight);
> WinDrawLine (x2, y2, x2, y2 - frameEndHeight);
> WinDrawLine (x2, y1 + frameEndHeight, x2 + frameEndWidth, y1 +
frameEndHeight);
> WinDrawLine (x2, y2 - frameEndHeight, x2 + frameEndWidth, y2 -
frameEndHeight);
> WinDrawLine (x2 + frameEndWidth, y1 + frameEndHeight,
> x2 + frameEndWidth, y2 - frameEndHeight);
>
> batteryGaugeWidth = r.extent.x - 2;
> batteryPowerWidth = (batteryPercent * batteryGaugeWidth + 50) / 100;
>
> batteryGaugeMainWidth = r.extent.x - frameEndWidth - 3;
> batteryGaugeEndWidth = batteryGaugeWidth - batteryGaugeMainWidth;
>
> // Draw the power indicator.
> gaugeMainR.topLeft.x = r.topLeft.x + 1;
> gaugeMainR.topLeft.y = r.topLeft.y + 1;
> gaugeMainR.extent.x = batteryGaugeMainWidth;
> gaugeMainR.extent.y = r.extent.y - 2;
>
> gaugeEndR.topLeft.x = r.topLeft.x + batteryGaugeMainWidth + 1;
> gaugeEndR.topLeft.y = r.topLeft.y + frameEndHeight + 1;
> gaugeEndR.extent.x = batteryGaugeEndWidth - 1;
> gaugeEndR.extent.y = r.extent.y - (frameEndHeight * 2) - 2;
>
> if (batteryPowerWidth < batteryGaugeMainWidth)
> gaugeMainR.extent.x = batteryPowerWidth;
> WinDrawRectangle (&gaugeMainR, 0);
>
> if (batteryPowerWidth < batteryGaugeMainWidth)
> {
> // And clear the battery which is used up
> gaugeMainR.topLeft.x += gaugeMainR.extent.x;
> gaugeMainR.extent.x = batteryGaugeMainWidth - gaugeMainR.extent.x;
> WinEraseRectangle (&gaugeMainR, 0);
> }
>
> if (batteryPowerWidth > batteryGaugeMainWidth)
> {
> gaugeEndR.extent.x = batteryPowerWidth - batteryGaugeMainWidth;
> WinDrawRectangle (&gaugeEndR, 0);
>
> gaugeEndR.topLeft.x += gaugeEndR.extent.x;
> gaugeEndR.extent.x = batteryGaugeEndWidth - gaugeEndR.extent.x;
> }
>
> WinEraseRectangle (&gaugeEndR, 0);
>}
My guess that updating the levels ever 15 seconds or so would not be
unreasonable.
Look up using the nilEvent message to drive your update.
----- Original Message -----
From: "John Crouch" <[EMAIL PROTECTED]>
Newsgroups: palm-dev-forum
To: "Palm Developer Forum" <[EMAIL PROTECTED]>
Sent: Wednesday, May 09, 2001 3:12 PM
Subject: Battery Meter
> I would like to create my own battery meter to visually display the
battery
> level when my app is running. I have searched the Palm app source code as
> well as the newsgroup for ideas on how to do this but could not find
> anything.
>
> I am particularly interested in:
>
> 1. How to display the visual battery on the screen. Some sort of gadget
> with a bitmap on top of it perhaps?
>
> 2. How to continually poll the battery so the display can be updated?
Would
> it be best to do this with an alarm, and if so how often is a reasonable
> amount of elapsed time without hogging processor time.
>
> If anyone can steer me in the right direction on how to do this I would
> appreciate it. Thanks.
>
>
>
>
>
> --
> For information on using the Palm Developer Forums, or to unsubscribe,
please see http://www.palmos.com/dev/tech/support/forums/
>
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