package com.coreprojects.calculator;
// Packages
import android.annotation.SuppressLint;
import android.app.Activity;
import android.content.ClipData;
import android.content.SharedPreferences;
import android.graphics.Typeface;
import android.os.Bundle;
import android.view.DragEvent;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.DragShadowBuilder;
import android.view.View.OnDragListener;
import android.view.View.OnTouchListener;
import android.view.Window;
import android.view.WindowManager;
import android.widget.Button;
import android.widget.TextView;
@SuppressLint("NewApi")
public class MainActivity extends Activity {
/**
* Variables. In java there are lots of type variables like C++
* In this case we use many type of variables, like:
* Private, String, Integer and so on.
* We must tell computer or JVM that we store some kind of information in RAM, so RAM must give us place to store
* 1. TextView must be private, we store information that are Text Kind.
* 2. String must public, we store operations, like 123, 3432, 323423 and so on...
* 3. result must be integer. we store numbers in strings to manipulate and retrieve results in integer type.
* 4. double is like float point numbers, 1.2, 2.3445 and so on [for calculator it is nessessery]
* ===============================================================================================================
* @author CoreProjects
* @category Software Engineer
* {@link http://coreprojects.org}
* !!!!! This all means that we used global variables, they will be accesable for every method without initializing
*/
private TextView display, resultPlace, dropped, dropTarget, delete;
private TextView choice1, choice2, choice3, choice4, choice5, choice6;
String Second_op;
/**
* Main function and method in Android Java
* It is like C++ int main() function, where all other classes and objects orient here.
* When developer writes code and classes and other .java files, we encapsulate everything here
*/
@Override
public void onCreate(Bundle savedInstanceState) {
// Creating new onCreate method, this means that we creating main program
super.onCreate(savedInstanceState);
// !!!! This must be after onCreate and means to hide all status and app bar
requestWindowFeature(Window.FEATURE_NO_TITLE);
this.getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
WindowManager.LayoutParams.FLAG_FULLSCREEN);
// Call in xml folder main xml file
setContentView(R.layout.activity_main);
/**
* this parameter finds the TextView by ID
* In this case these textviews are draggable.
* we find the place and then manipulate them to be draggable.
* display = place where touched numbers are displayed
* calcresult = place where we show result and than manipulate to drag in delete or somewhere
*/
display = (TextView) findViewById(R.id.display);
delete = (TextView) findViewById(R.id.calcResult);
// TextView Place where we can drop dragged items
choice1 = (TextView) findViewById(R.id.gamokleba);
choice2 = (TextView) findViewById(R.id.mimateba);
choice3 = (TextView) findViewById(R.id.gamravleba);
choice4 = (TextView) findViewById(R.id.gayofa);
choice5 = (TextView) findViewById(R.id.procenti);
choice6 = (TextView) findViewById(R.id.delete);
// Create droppable classes to do action
display.setOnTouchListener(new ChoiceTouchListener());
delete.setOnTouchListener(new ChoiceTouchListener());
// Create dragable classes to do action
choice1.setOnDragListener(new ChoiceDragListener());
choice2.setOnDragListener(new ChoiceDragListener());
choice3.setOnDragListener(new ChoiceDragListener());
choice4.setOnDragListener(new ChoiceDragListener());
choice5.setOnDragListener(new ChoiceDragListener());
choice6.setOnDragListener(new ChoiceDragListener());
// Here we useing custom font family
Typeface Face = Typeface.createFromAsset(getAssets(), "fonts/font.ttf");
// Setting which TextView will using this font
delete.setTypeface(Face);
display.setTypeface(Face);
choice1.setTypeface(Face);
choice2.setTypeface(Face);
choice3.setTypeface(Face);
choice4.setTypeface(Face);
choice5.setTypeface(Face);
}
/**
* Main method
* We using this method to make items touchable and dragable
* Then we use them to drop an manipulate what we want
* @author Administrator
*
*/
private class ChoiceDragListener implements OnDragListener {
// onDrag Method, imagine we dragging numbers from display TextView
@Override
public boolean onDrag(View v, DragEvent event) {
// Android has onDrag action types. there are some kind of action
switch (event.getAction()) {
// if drag stared
case DragEvent.ACTION_DRAG_STARTED:
break;
// if drag entered software
case DragEvent.ACTION_DRAG_ENTERED:
break;
// if drag exited, stopped or something
case DragEvent.ACTION_DRAG_EXITED:
break;
// main case, if drag dropped what we do...
case DragEvent.ACTION_DROP:
// handle the dragged view being dropped over a drop view
View view = (View) event.getLocalState();
// stop displaying the view where it was before it was dragged
// ************* view.setVisibility(View.KEEP_SCREEN_ON);
// view dragged item, where numbers will be dragged
dropTarget = (TextView) v;
// view dropped item, that will be dropped in drag TextView
dropped = (TextView) view;
// view result place, when make math operation, show results
resultPlace = (TextView) findViewById(R.id.calcResult);
// simple debug
// ****** resultPlace.setText( dropped.getText() + " " + dropTarget.getText() );
// if an item has already been dropped here, there will be a tag
Object tag = dropTarget.getTag();
SharedPreferences myPrefs = getSharedPreferences("myPrefs", MODE_PRIVATE);
// if there is already an item here, set it back visible in its
// original place
if (tag != null)
{
// the tag is the view id already dropped here
int existingID = (Integer) tag;
// set the original view visible again
findViewById(existingID).setVisibility(View.VISIBLE);
} else {
myPrefs.edit()
.putString("Second_op", (String) dropped.getText())
.commit();
Second_op = myPrefs.getString("Second_op", null);
}
int a = Integer.parseInt(dropped.getText().toString());
int b = Integer.parseInt(Second_op);
if ( dropTarget.getText().equals("+") && a != 0 && b != 0 ){
int res = a + b;
String result = Integer.toString(res);
resultPlace.setText( result );
myPrefs.edit().clear().commit();
} else {
resultPlace.setText( "Text" );
}
// ****** resultPlace.setText( dropped.getText() + " " + dropTarget.getText() + " " + Second_op );
// set the tag in the target view being dropped on - to the ID
// of the view being dropped
dropTarget.setTag(dropped.getId());
display.setText("");
break;
// if drag ended, we did it already successfully
case DragEvent.ACTION_DRAG_ENDED:
break;
// what do default
default:
break;
}
return true;
}
}
// second main method make this selected items touchable, to understand device we use them
@SuppressLint("NewApi")
private final class ChoiceTouchListener implements OnTouchListener {
public boolean onTouch(View view, MotionEvent motionEvent) {
if (motionEvent.getAction() == MotionEvent.ACTION_DOWN) {
/*
* Drag details: we only need default behavior - clip data could
* be set to pass data as part of drag - shadow can be tailored
*/
ClipData data = ClipData.newPlainText("", "");
DragShadowBuilder shadowBuilder = new View.DragShadowBuilder(view);
// start dragging the item touched
view.startDrag(data, shadowBuilder, view, 0);
return true;
} else {
return false;
}
}
}
/**
* Most neccessery one
* When we touching and clicking number buttons we display 1, 2, 3, 4, 5 and so on
* But if we want to have number like 388201, we create it by this function
* Click digit 2 and when we also click second digit 8, it is appended and got 28
* @param v
*/
public void updateDisplay(View v) {
// Local variables, we only use them in this method
display = (TextView) findViewById(R.id.display);
Button button1 = (Button) findViewById(R.id.button01);
button1.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
display.setText(display.getText().toString() + ((Button) view).getText());
}
});
// Create new text that will be set in display TextView | local variable
display.setText(display.getText().toString() + ((Button) v).getText());
}
}
这是我的代码。我正在尝试创建拖放计算器。我有从 0 到 9 的数字；
1 2 3 4 5 6 7 8 9 0
单击它们，并创建像243这样的数字，它们在数学运算中触摸并拖动，例如+ 加号，然后创建第二个数字并在相同的数学运算中拖放。在这里我有问题，我试图在某处存储第一个值及其操作，因为当我删除秒值时，第一个值也更新了。我使用了SharedPreferences，但是当我得到结果然后将这个结果拖到操作中时，应用程序停止了。想通了，这就是 Pereferences 问题。我该如何解决这个问题？我想从两个数字中得到结果，然后也可以拖动结果。
230 + 330 = 560
560——新掉号？（当我拖放结果值时应用程序停止）