Hi all,
what would be the simplest approach to embedd moving, clickable and draggable bitmaps as threads within a main Component? Trying to incorporate a button thread, for example, seems not to be displayed at all in the main component, only the paint() method works, but the default button graphics are not.
Am I misunderstanding something?
Thanks in advance!
Josep M
There is no “Bitmap” class…
I’m struggling to understand what you’re trying to do or why you want a thread to be involved?
[quote=“jeppius”]Thanks Jules,
I mean adding a Thread which is a subclass of Bitmap as well.[/quote]
Sorry, a subclass of ImageButton
Indeed maybe threads are not required at all to make moving bitmaps appear and disappear…
Indeed, I just wanted to make clickable the moving balls from the Multithreading example in the Juce Demo app. 
Josep M
[quote=“jules”]There is no “Bitmap” class…
I’m struggling to understand what you’re trying to do or why you want a thread to be involved?[/quote]
Why not just make the object that represents the moving balls inherit from juce::Button instead of juce::Component…?
and for the record - those “balls” are not raster images (ie: Bitmaps); they’re filled paths!
Sure,
but when I do that (when I subclass BouncingBallComp from, for example, TextButton) shouldn’t be visible a default button inside the ball?
Why not just make the object that represents the moving balls inherit from juce::Button instead of juce::Component…?[/quote]
For one, I don’t think the juce:TextButton is designed to be a base class.
Also, it seems that you’re expecting an actual button-like shape to appear, with button functionality, inside the circle - that would be absolutely incorrect! I strongly suggest picking up a C++ book to understand what inheritance means, and analyze the design of the juce::Button base class.
For what you want; the “ball” should be inheriting the juce::Button, you are to implement the proper, related methods - and you have a functional button! The ball becomes becomes the button - no other graphics of any kind would appear. Also, you must add and remove the ThreadingDemo Component as listener to the BouncingBallComp subclasses appropriately.
Copy-paste this over everything in ThreadingDemo.cpp in the JUCE Demo.
This file is part of the JUCE library - "Jules’ Utility Class Extensions"
Copyright 2004-9 by Raw Material Software Ltd.
JUCE can be redistributed and/or modified under the terms of the GNU General
Public License (Version 2), as published by the Free Software Foundation.
A copy of the license is included in the JUCE distribution, or can be found
online at www.gnu.org/licenses.
JUCE is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
A PARTICULAR PURPOSE. See the GNU General Public License for more details.
To release a closed-source product which uses JUCE, commercial licenses are
available: visit www.rawmaterialsoftware.com/juce for more information.
==============================================================================
*/
#include “…/jucedemo_headers.h”
//==============================================================================
class BouncingBallComp : public juce::Button
{
public:
BouncingBallComp() :
Button (“Some Button Name”)
{
x = Random::getSystemRandom().nextFloat() * 200.0f;
y = Random::getSystemRandom().nextFloat() * 200.0f;
parentWidth = 50;
parentHeight = 50;
innerX = 0;
innerY = 0;
threadId = 0;
const float speed = 5.0f; // give each ball a fixed speed so we can
// see the effects of thread priority on how fast
// they actually go.
const float angle = Random::getSystemRandom().nextFloat() * float_Pi * 2.0f;
dx = sinf (angle) * speed;
dy = cosf (angle) * speed;
size = Random::getSystemRandom().nextFloat() * 30.0f + 30.0f;
colour = Colour (Random::getSystemRandom().nextInt())
.withAlpha (0.5f)
.withBrightness (0.7f);
}
~BouncingBallComp()
{
}
void paint (Graphics& g)
{
g.setColour (colour);
g.fillEllipse (innerX, innerY, size, size);
g.setColour (Colours::black);
g.setFont (10.0f);
g.drawText (String::toHexString ((int64) threadId), 0, 0, getWidth(), getHeight(), Justification::centred, false);
}
void parentSizeChanged()
{
parentWidth = getParentWidth() - size;
parentHeight = getParentHeight() - size;
}
void paintButton (Graphics& g, bool isMouseOverButton, bool isButtonDown)
{
}
void moveBall()
{
threadId = Thread::getCurrentThreadId(); // this is so the component can print the thread ID inside the ball
x += dx;
y += dy;
if (x < 0)
dx = fabsf (dx);
if (x > parentWidth)
dx = -fabsf (dx);
if (y < 0)
dy = fabsf (dy);
if (y > parentHeight)
dy = -fabsf (dy);
setBounds (((int) x) - 2,
((int) y) - 2,
((int) size) + 4,
((int) size) + 4);
innerX = x - getX();
innerY = y - getY();
repaint();
}
private:
float x, y, size, dx, dy, w, h, parentWidth, parentHeight;
float innerX, innerY;
Colour colour;
Thread::ThreadID threadId;
JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (BouncingBallComp);
};
//==============================================================================
class DemoThread : public BouncingBallComp,
public Thread
{
public:
DemoThread()
: Thread (“Juce Demo Thread”)
{
interval = Random::getSystemRandom().nextInt (50) + 6;
// give the threads a random priority, so some will move more
// smoothly than others..
startThread (Random::getSystemRandom().nextInt (3) + 3);
}
~DemoThread()
{
// allow the thread 2 seconds to stop cleanly - should be plenty of time.
stopThread (2000);
}
void run()
{
// this is the code that runs this thread - we'll loop continuously,
// updating the co-ordinates of our blob.
// threadShouldExit() returns true when the stopThread() method has been
// called, so we should check it often, and exit as soon as it gets flagged.
while (! threadShouldExit())
{
// sleep a bit so the threads don't all grind the CPU to a halt..
wait (interval);
// because this is a background thread, we mustn't do any UI work without
// first grabbing a MessageManagerLock..
const MessageManagerLock mml (Thread::getCurrentThread());
if (! mml.lockWasGained()) // if something is trying to kill this job, the lock
return; // will fail, in which case we'd better return..
// now we've got the UI thread locked, we can mess about with the components
moveBall();
}
}
private:
int interval;
JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (DemoThread);
};
//==============================================================================
class DemoThreadPoolJob : public BouncingBallComp,
public ThreadPoolJob
{
public:
DemoThreadPoolJob()
: ThreadPoolJob (“Demo Threadpool Job”)
{
}
JobStatus runJob()
{
// this is the code that runs this job. It'll be repeatedly called until we return
// jobHasFinished instead of jobNeedsRunningAgain.
Thread::sleep (30);
// because this is a background thread, we mustn't do any UI work without
// first grabbing a MessageManagerLock..
const MessageManagerLock mml (this);
// before moving the ball, we need to check whether the lock was actually gained, because
// if something is trying to stop this job, it will have failed..
if (mml.lockWasGained())
moveBall();
return jobNeedsRunningAgain;
}
void removedFromQueue()
{
// This is called to tell us that our job has been removed from the pool.
// In this case there's no need to do anything here.
}
private:
JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (DemoThreadPoolJob);
};
//==============================================================================
class ThreadingDemo : public Component,
public Timer,
public ButtonListener
{
public:
//==============================================================================
ThreadingDemo()
: pool (3),
controlButton (“Thread type”),
isUsingPool (false)
{
setName (“Multithreading”);
setOpaque (true);
addAndMakeVisible (&controlButton);
controlButton.changeWidthToFitText (20);
controlButton.setTopLeftPosition (20, 20);
//controlButton.setTriggeredOnMouseDown (true);
controlButton.setAlwaysOnTop (true);
//controlButton.addListener (this);
}
~ThreadingDemo()
{
pool.removeAllJobs (true, 2000);
}
void resetAllBalls()
{
stopTimer();
pool.removeAllJobs (true, 4000);
balls.clear();
if (isShowing())
{
while (balls.size() < 5)
addABall();
startTimer (300);
}
}
void paint (Graphics& g)
{
g.fillAll (Colours::white);
}
void setUsingPool (bool usePool)
{
isUsingPool = usePool;
resetAllBalls();
}
void addABall()
{
if (isUsingPool)
{
DemoThreadPoolJob* newBall = new DemoThreadPoolJob();
balls.add (newBall);
addAndMakeVisible (newBall);
newBall->parentSizeChanged();
newBall->addButtonListener (this);
pool.addJob (newBall, false);
}
else
{
DemoThread* newBall = new DemoThread();
newBall->addButtonListener (this);
balls.add (newBall);
addAndMakeVisible (newBall);
newBall->parentSizeChanged();
}
}
void removeABall()
{
if (balls.size() > 0)
{
int indexToRemove = Random::getSystemRandom().nextInt (balls.size());
if (isUsingPool)
pool.removeJob (dynamic_cast <DemoThreadPoolJob*> (balls [indexToRemove]), true, 4000);
balls.remove (indexToRemove);
}
}
void timerCallback()
{
if (Random::getSystemRandom().nextBool())
{
if (balls.size() <= 10)
addABall();
}
else
{
if (balls.size() > 3)
removeABall();
}
}
void buttonClicked (Button* button)
{
if (button == &controlButton)
{
PopupMenu m;
m.addItem (1, "Use one thread per ball", true, ! isUsingPool);
m.addItem (2, "Use a thread pool", true, isUsingPool);
m.showMenuAsync (PopupMenu::Options().withTargetComponent (&controlButton),
ModalCallbackFunction::forComponent (menuItemChosenCallback, this));
}
else
{
for (int i = 0; i < balls.size(); ++i)
{
if (button == balls[i])
{
DBG ("Ball was clicked!");
}
}
}
}
static void menuItemChosenCallback (int result, ThreadingDemo* demoComponent)
{
if (demoComponent != 0)
demoComponent->setUsingPool (result == 2);
}
// this gets called when a component is added or removed from a parent component.
void parentHierarchyChanged()
{
// we'll use this as an opportunity to start and stop the threads, so that
// we don't leave them going when the component's not actually visible.
resetAllBalls();
}
private:
ThreadPool pool;
TextButton controlButton;
bool isUsingPool;
OwnedArray<Component> balls;
};
//==============================================================================
Component* createThreadingDemo()
{
return new ThreadingDemo();
}[/code]
Got it, thanks for clarifying that!
Now I’m trying to make such balls draggable (solved) and droppable into another component (still working on it…). Any available exemple of drag&drop component interaction besides the Demo?
Josep M
[quote=“jrlanglois”]Copy-paste this over everything in ThreadingDemo.cpp in the JUCE Demo.
This file is part of the JUCE library - "Jules’ Utility Class Extensions"
Copyright 2004-9 by Raw Material Software Ltd.
JUCE can be redistributed and/or modified under the terms of the GNU General
Public License (Version 2), as published by the Free Software Foundation.
A copy of the license is included in the JUCE distribution, or can be found
online at www.gnu.org/licenses.
JUCE is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
A PARTICULAR PURPOSE. See the GNU General Public License for more details.
To release a closed-source product which uses JUCE, commercial licenses are
available: visit www.rawmaterialsoftware.com/juce for more information.
==============================================================================
*/
#include “…/jucedemo_headers.h”
//==============================================================================
class BouncingBallComp : public juce::Button
{
public:
BouncingBallComp() :
Button (“Some Button Name”)
{
x = Random::getSystemRandom().nextFloat() * 200.0f;
y = Random::getSystemRandom().nextFloat() * 200.0f;
parentWidth = 50;
parentHeight = 50;
innerX = 0;
innerY = 0;
threadId = 0;
const float speed = 5.0f; // give each ball a fixed speed so we can
// see the effects of thread priority on how fast
// they actually go.
const float angle = Random::getSystemRandom().nextFloat() * float_Pi * 2.0f;
dx = sinf (angle) * speed;
dy = cosf (angle) * speed;
size = Random::getSystemRandom().nextFloat() * 30.0f + 30.0f;
colour = Colour (Random::getSystemRandom().nextInt())
.withAlpha (0.5f)
.withBrightness (0.7f);
}
~BouncingBallComp()
{
}
void paint (Graphics& g)
{
g.setColour (colour);
g.fillEllipse (innerX, innerY, size, size);
g.setColour (Colours::black);
g.setFont (10.0f);
g.drawText (String::toHexString ((int64) threadId), 0, 0, getWidth(), getHeight(), Justification::centred, false);
}
void parentSizeChanged()
{
parentWidth = getParentWidth() - size;
parentHeight = getParentHeight() - size;
}
void paintButton (Graphics& g, bool isMouseOverButton, bool isButtonDown)
{
}
void moveBall()
{
threadId = Thread::getCurrentThreadId(); // this is so the component can print the thread ID inside the ball
x += dx;
y += dy;
if (x < 0)
dx = fabsf (dx);
if (x > parentWidth)
dx = -fabsf (dx);
if (y < 0)
dy = fabsf (dy);
if (y > parentHeight)
dy = -fabsf (dy);
setBounds (((int) x) - 2,
((int) y) - 2,
((int) size) + 4,
((int) size) + 4);
innerX = x - getX();
innerY = y - getY();
repaint();
}
private:
float x, y, size, dx, dy, w, h, parentWidth, parentHeight;
float innerX, innerY;
Colour colour;
Thread::ThreadID threadId;
JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (BouncingBallComp);
};
//==============================================================================
class DemoThread : public BouncingBallComp,
public Thread
{
public:
DemoThread()
: Thread (“Juce Demo Thread”)
{
interval = Random::getSystemRandom().nextInt (50) + 6;
// give the threads a random priority, so some will move more
// smoothly than others..
startThread (Random::getSystemRandom().nextInt (3) + 3);
}
~DemoThread()
{
// allow the thread 2 seconds to stop cleanly - should be plenty of time.
stopThread (2000);
}
void run()
{
// this is the code that runs this thread - we'll loop continuously,
// updating the co-ordinates of our blob.
// threadShouldExit() returns true when the stopThread() method has been
// called, so we should check it often, and exit as soon as it gets flagged.
while (! threadShouldExit())
{
// sleep a bit so the threads don't all grind the CPU to a halt..
wait (interval);
// because this is a background thread, we mustn't do any UI work without
// first grabbing a MessageManagerLock..
const MessageManagerLock mml (Thread::getCurrentThread());
if (! mml.lockWasGained()) // if something is trying to kill this job, the lock
return; // will fail, in which case we'd better return..
// now we've got the UI thread locked, we can mess about with the components
moveBall();
}
}
private:
int interval;
JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (DemoThread);
};
//==============================================================================
class DemoThreadPoolJob : public BouncingBallComp,
public ThreadPoolJob
{
public:
DemoThreadPoolJob()
: ThreadPoolJob (“Demo Threadpool Job”)
{
}
JobStatus runJob()
{
// this is the code that runs this job. It'll be repeatedly called until we return
// jobHasFinished instead of jobNeedsRunningAgain.
Thread::sleep (30);
// because this is a background thread, we mustn't do any UI work without
// first grabbing a MessageManagerLock..
const MessageManagerLock mml (this);
// before moving the ball, we need to check whether the lock was actually gained, because
// if something is trying to stop this job, it will have failed..
if (mml.lockWasGained())
moveBall();
return jobNeedsRunningAgain;
}
void removedFromQueue()
{
// This is called to tell us that our job has been removed from the pool.
// In this case there's no need to do anything here.
}
private:
JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (DemoThreadPoolJob);
};
//==============================================================================
class ThreadingDemo : public Component,
public Timer,
public ButtonListener
{
public:
//==============================================================================
ThreadingDemo()
: pool (3),
controlButton (“Thread type”),
isUsingPool (false)
{
setName (“Multithreading”);
setOpaque (true);
addAndMakeVisible (&controlButton);
controlButton.changeWidthToFitText (20);
controlButton.setTopLeftPosition (20, 20);
//controlButton.setTriggeredOnMouseDown (true);
controlButton.setAlwaysOnTop (true);
//controlButton.addListener (this);
}
~ThreadingDemo()
{
pool.removeAllJobs (true, 2000);
}
void resetAllBalls()
{
stopTimer();
pool.removeAllJobs (true, 4000);
balls.clear();
if (isShowing())
{
while (balls.size() < 5)
addABall();
startTimer (300);
}
}
void paint (Graphics& g)
{
g.fillAll (Colours::white);
}
void setUsingPool (bool usePool)
{
isUsingPool = usePool;
resetAllBalls();
}
void addABall()
{
if (isUsingPool)
{
DemoThreadPoolJob* newBall = new DemoThreadPoolJob();
balls.add (newBall);
addAndMakeVisible (newBall);
newBall->parentSizeChanged();
newBall->addButtonListener (this);
pool.addJob (newBall, false);
}
else
{
DemoThread* newBall = new DemoThread();
newBall->addButtonListener (this);
balls.add (newBall);
addAndMakeVisible (newBall);
newBall->parentSizeChanged();
}
}
void removeABall()
{
if (balls.size() > 0)
{
int indexToRemove = Random::getSystemRandom().nextInt (balls.size());
if (isUsingPool)
pool.removeJob (dynamic_cast <DemoThreadPoolJob*> (balls [indexToRemove]), true, 4000);
balls.remove (indexToRemove);
}
}
void timerCallback()
{
if (Random::getSystemRandom().nextBool())
{
if (balls.size() <= 10)
addABall();
}
else
{
if (balls.size() > 3)
removeABall();
}
}
void buttonClicked (Button* button)
{
if (button == &controlButton)
{
PopupMenu m;
m.addItem (1, "Use one thread per ball", true, ! isUsingPool);
m.addItem (2, "Use a thread pool", true, isUsingPool);
m.showMenuAsync (PopupMenu::Options().withTargetComponent (&controlButton),
ModalCallbackFunction::forComponent (menuItemChosenCallback, this));
}
else
{
for (int i = 0; i < balls.size(); ++i)
{
if (button == balls[i])
{
DBG ("Ball was clicked!");
}
}
}
}
static void menuItemChosenCallback (int result, ThreadingDemo* demoComponent)
{
if (demoComponent != 0)
demoComponent->setUsingPool (result == 2);
}
// this gets called when a component is added or removed from a parent component.
void parentHierarchyChanged()
{
// we'll use this as an opportunity to start and stop the threads, so that
// we don't leave them going when the component's not actually visible.
resetAllBalls();
}
private:
ThreadPool pool;
TextButton controlButton;
bool isUsingPool;
OwnedArray<Component> balls;
};
//==============================================================================
Component* createThreadingDemo()
{
return new ThreadingDemo();
}[/code][/quote]
I’m not certain right off-hand, and could check, but I know of these classes:
http://www.rawmaterialsoftware.com/juce/api_latest/classDragAndDropContainer.html
http://www.rawmaterialsoftware.com/juce/api_latest/classDragAndDropTarget.html