Add mock part addition/deletion mechanism.

app/src/main/java/com/codigoparallevar/minicards/CanvasView.java

@@ -1,5 +1,6 @@
 package com.codigoparallevar.minicards;
 
+import android.app.Activity;
 import android.content.Context;
 import android.graphics.Canvas;
 import android.graphics.Color;
@@ -16,6 +17,7 @@ import com.codigoparallevar.minicards.parts.Part;
 import com.codigoparallevar.minicards.parts.Placeholder;
 import com.codigoparallevar.minicards.parts.buttons.RoundButton;
 import com.codigoparallevar.minicards.parts.types.Position;
+import com.getbase.floatingactionbutton.FloatingActionsMenu;
 
 import org.json.JSONArray;
 import org.json.JSONException;
@@ -47,6 +49,9 @@ class CanvasView extends View {
     @NonNull
     private String name = "default";
     private final static float touchTimeForLongTouchInMillis = 500;
+    private boolean _isDragging = false;
+    private MainActivity parentActivity = null;
+    private Tuple<Integer, Integer, Integer, Integer> _dropZone = new Tuple<>(0, 0, 0, 0);
 
     public CanvasView(Context context) {
         super(context);
@@ -173,7 +178,16 @@ class CanvasView extends View {
                         selectedPart.touched();
                     }
                 }
+                else if (motionMode == MotionMode.Type.LongTouch) {
+                    if (selectedPart != null) {
+                        if (inDropZone(x, y)) {
+                            Log.d("Canvas", "Deleting element" + selectedPart);
+                            parts.remove(selectedPart);
+                        }
+                    }
+                }
 
+                _isDragging = false;
                 motionMode = null;
                 selectedPart = null;
             }
@@ -186,6 +200,8 @@ class CanvasView extends View {
 
             case MotionEvent.ACTION_MOVE:
             {
+                Log.i("Canvas", "X: " + x + " Y: " + y
+                        + " in drop zone " + _dropZone  + " : " + inDropZone(x, y));
                 if (motionMode == null){
                     final Part nowSelectedPart = getPartOn(x, y);
                     final boolean canWait = selectedPart == nowSelectedPart;
@@ -193,6 +209,7 @@ class CanvasView extends View {
                 }
                 if (motionMode == MotionMode.Type.LongTouch){
                     if (selectedPart != null){
+                        _isDragging = true;
                         selectedPart.move(x, y);
                     }
                 }
@@ -206,9 +223,17 @@ class CanvasView extends View {
         }
 
         invalidate();
+        if (parentActivity != null) {
+            parentActivity.invalidate();
+        }
         return true;
     }
 
+    private boolean inDropZone(int x, int y) {
+        return (x >= _dropZone._x1) && (x <= _dropZone._x2)
+                && (y >= _dropZone._y1) && (y <= _dropZone._y2);
+    }
+
     private void saveState() throws IOException {
         File filesDir = getContext().getFilesDir();
         FileOutputStream fileOut = new FileOutputStream(filesDir + "/" + name);
@@ -270,4 +295,36 @@ class CanvasView extends View {
         parts.add(part);
         invalidate();
     }
+
+    public boolean isDragging() {
+        return _isDragging;
+    }
+
+    public void setParentActivity(MainActivity parentActivity) {
+        this.parentActivity = parentActivity;
+    }
+
+    public void setDropZone(float x1, float x2, float y1, float y2) {
+        _dropZone = new Tuple<>((int) x1, (int) x2, (int) y1, (int) y2);
+    }
+
+    private class Tuple<T, T1, T2, T3> {
+
+        final T _x1;
+        final T1 _x2;
+        final T2 _y1;
+        final T3 _y2;
+
+        public Tuple(T x1, T1 x2, T2 y1, T3 y2) {
+            _x1 = x1;
+            _x2 = x2;
+            _y1 = y1;
+            _y2 = y2;
+        }
+
+        @Override
+        public String toString(){
+            return "(" + _x1 + " - " + _x2 + ", " + _y1 + " - " + _y2 + ")";
+        }
+    }
 }

app/src/main/java/com/codigoparallevar/minicards/MainActivity.java

@@ -1,6 +1,5 @@
 package com.codigoparallevar.minicards;
 
-import android.graphics.Canvas;
 import android.support.design.widget.FloatingActionButton;
 import android.support.design.widget.Snackbar;
 import android.support.v7.app.ActionBar;
@@ -9,16 +8,16 @@ import android.os.Bundle;
 import android.util.Log;
 import android.view.MotionEvent;
 import android.view.View;
-import android.widget.Button;
 
 import com.codigoparallevar.minicards.parts.buttons.RoundButton;
-import com.getbase.floatingactionbutton.AddFloatingActionButton;
 
 public class MainActivity extends AppCompatActivity {
 
     CanvasView canvasView;
     com.getbase.floatingactionbutton.AddFloatingActionButton AddPartButton;
     com.getbase.floatingactionbutton.FloatingActionButton SetDevModeButton;
+    com.getbase.floatingactionbutton.FloatingActionsMenu fabMenu;
+    FloatingActionButton removePartFab;
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
@@ -34,13 +33,25 @@ public class MainActivity extends AppCompatActivity {
 
         // Use manually controlled canvas
         canvasView = (CanvasView) findViewById(R.id.canvasView);
+        canvasView.setParentActivity(this);
+
+        removePartFab = (FloatingActionButton) findViewById(R.id.remove_part_fab);
+        canvasView.setDropZone(
+                removePartFab.getX(), removePartFab.getX() + removePartFab.getWidth(),
+                removePartFab.getY(), removePartFab.getY() + removePartFab.getHeight());
 
         // Set callbacks to fab buttons
+        fabMenu = (com.getbase.floatingactionbutton.FloatingActionsMenu)
+                findViewById(R.id.fab);
+
         AddPartButton = (com.getbase.floatingactionbutton.AddFloatingActionButton)
                 findViewById(R.id.add_part_button);
         AddPartButton.setOnClickListener(new View.OnClickListener() {
             @Override
             public void onClick(View v) {
+                if (canvasView != null) {
+                    canvasView.addPart(new RoundButton(500, 500, 50, 100));
+                }
                 Snackbar.make(v, "Add part", Snackbar.LENGTH_SHORT).show();
             }
         });
@@ -65,4 +76,22 @@ public class MainActivity extends AppCompatActivity {
 
         return super.onTouchEvent(event);
     }
+
+    public void invalidate() {
+        if (canvasView != null){
+            if (canvasView.isDragging()){
+                fabMenu.setVisibility(View.GONE);
+                removePartFab.setVisibility(View.VISIBLE);
+                Log.d("Main", "Changing visibility!");
+            }
+            else {
+                fabMenu.setVisibility(View.VISIBLE);
+                removePartFab.setVisibility(View.GONE);
+                Log.d("Main", "Now changing visibility!");
+            }
+            canvasView.setDropZone(
+                    removePartFab.getX(), removePartFab.getX() + removePartFab.getWidth(),
+                    removePartFab.getY(), removePartFab.getY() + removePartFab.getHeight());
+        }
+    }
 }

app/src/main/res/layout/activity_main.xml

@@ -29,6 +29,16 @@
         android:layout_width="match_parent"
         android:layout_height="match_parent" />
 
+    <android.support.design.widget.FloatingActionButton
+        android:id="@+id/remove_part_fab"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_gravity="bottom|end"
+        android:layout_margin="@dimen/fab_margin"
+        android:visibility="gone"
+        android:background="@color/white"
+        app:srcCompat="@android:drawable/ic_delete" />
+
     <com.getbase.floatingactionbutton.FloatingActionsMenu
         android:id="@+id/fab"
         android:layout_width="wrap_content"