Implement click detection.

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

@@ -5,19 +5,19 @@ import android.graphics.Canvas;
 import android.graphics.Color;
 import android.graphics.Paint;
 import android.util.Log;
+import android.view.MotionEvent;
 import android.view.View;
 
 import com.codigoparallevar.minicards.parts.Part;
 import com.codigoparallevar.minicards.parts.Placeholder;
 import com.codigoparallevar.minicards.parts.buttons.RoundButton;
 
-import java.util.LinkedList;
-import java.util.List;
+import java.util.ArrayList;
 
 class DrawView extends View {
 
     Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
-    List<Part> parts = new LinkedList<>();
+    ArrayList<Part> parts = new ArrayList<>();
 
     public DrawView(Context context) {
         super(context);
@@ -34,4 +34,32 @@ class DrawView extends View {
 
         Log.d("Render time", System.currentTimeMillis() - time + "ms");
     }
+
+    @Override
+    public boolean onTouchEvent(MotionEvent event){
+        int x = (int) event.getX() - this.getLeft();
+        int y = (int) event.getY() - this.getTop();
+
+        Part touchedPart = getPartOn(x, y);
+        if (touchedPart == null){
+            Log.d("Touched part", "not found");
+            return false;
+        }
+
+        Log.d("Touched part", "Part: " + touchedPart);
+        invalidate();
+        return true;
+    }
+
+    private Part getPartOn(int x, int y) {
+        // Look in the list, in reverse so top-most elements are checked before
+        for (int i = parts.size() - 1; i >= 0; i--){
+            Part part = parts.get(i);
+            if ((x >= part.getLeft()) && (part.getRight() >= x)
+                    && (y >= part.getTop()) && (part.getBottom() >= y)){
+                return part;
+            }
+        }
+        return null;
+    }
 }

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

@@ -3,15 +3,23 @@ package com.codigoparallevar.minicards;
 import android.graphics.Color;
 import android.support.v7.app.AppCompatActivity;
 import android.os.Bundle;
+import android.view.MotionEvent;
 
 public class TestActivity extends AppCompatActivity {
 
+    DrawView drawView;
+
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
 
-        DrawView drawView = new DrawView(this);
+        drawView = new DrawView(this);
         drawView.setBackgroundColor(Color.BLACK);
         setContentView(drawView);
     }
+
+    @Override
+    public boolean onTouchEvent(MotionEvent event) {
+        return drawView.onTouchEvent(event);
+    }
 }