Cascades Development

[KernelPanic]

I'm looking for a way to manipulate the blinking frequency of the device LED using Cascades.

So far I'm able to  access the LED and change its color. I can't find any mention about the blinking frequency in the API documentation. Does one have a pointer on how to achieve this?

Thanks 

Chris

[rlvl]

Looking at this http://developer.blackberry.com/cascades/reference/bb__device__led.html I see no way to manipulate the frequency 

[KernelPanic]

Thanks for your answer and your reference to the documentation. Too bad this isn't possible.

[slashkyle]

there's currently an open feature request to be able to do more with the LED api

suggest your use case & hopefully they'll do it, there's several other reasons why the api should be updated

https://www.blackberry.com/jira/browse/BBTEN-847

[KernelPanic]

[x] Done.

Thanks for the pointer.

[Zmey]

Even with current API blink frequency can be controlled by using a QTimer and calling led() function as frequently as needed.

However, specifying 1 as blink count does not work correctly, so don't specify it and call stop() manually when done.

Of course this won't work if the app is paused. But it works when the app is running in background.

[slashkyle]

for apps working with the led is it possible to tell if a incoming message has been read & stop it then

[KernelPanic]

I don't get it to work. Is it possible to show me a code snippet illustrating this?

Edit: I mean the use of led() with a timer.

[Zmey · Accepted solution]

I've created a test project where you can move the slider to set the led frequency.

'Start' button starts the blinking.

Download:

Test.zip

Test.hpp:

namespace bb { namespace device { class Led; }}
class QTimer;

class Test : public QObject
{
    Q_OBJECT
public:
    Test(bb::cascades::Application *app);
    virtual ~Test() {}

    Q_INVOKABLE void blink(int frequency);
    Q_INVOKABLE void stopBlinking();

public slots:
    void onTimer();

protected:
    QTimer *timer_;
    bb::device::Led *led_;
};

 Test.cpp:

#include <bb/device/Led>
#include <QTimer>

using namespace bb::cascades;
using namespace bb::device;

Test::Test(bb::cascades::Application *app)
: QObject(app)
{
    QmlDocument *qml = QmlDocument::create("asset:///main.qml").parent(this);

    qml->setContextProperty("app", this);
    AbstractPane *root = qml->createRootObject<AbstractPane>();
    app->setScene(root);

    led_ = new Led(LedColor::Green, this);

    timer_ = new QTimer(this);
    QObject::connect(timer_, SIGNAL(timeout()),
    		this, SLOT(onTimer()));
}

void Test::blink(int frequency)
{
    timer_->start(frequency);
    led_->flash();
}

void Test::stopBlinking()
{
    led_->cancel();
    timer_->stop();
}

void Test::onTimer()
{
    led_->cancel();
    led_->flash();
}

Test.pro:

LIBS += -lbbdevice

 bar-descriptor.xml:

    <permission>access_led_control</permission>

 main.qml:

import bb.cascades 1.0

Page {
    property bool stopped: true
    Container {
        Slider {
            id: frequencySlider
            fromValue: 1000
            toValue: 30
            value: 500
            onValueChanged: {
                if (!stopped)
                    app.blink(frequencySlider.value)
            }
        }
        Label {
            text: 'Frequency: ' + Math.floor(frequencySlider.value) + ' msec'
        }
        Button {
            text: "Start"
            onClicked: {
                app.blink(frequencySlider.value)
                stopped = false
            }
        }
        Button {
            text: "Stop"
            onClicked: {
                app.stopBlinking()
                stopped = true
            }
        }
    }
}

[KernelPanic]

Wow - thank you very much for your effort, I really appreciate that.
That is exactly what I was looking for but failed to discover it in the documentation.