tweaks to matrices

Xlythe · Jul 12, 2015 · 50e71c8 · 50e71c8
1 parent 71cf698
commit 50e71c8
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Showing 5 changed files with 87 additions and 9 deletions.
diff --git a/MathLibrary/src/main/java/com/xlythe/math/MatrixModule.java b/MathLibrary/src/main/java/com/xlythe/math/MatrixModule.java
@@ -7,6 +7,7 @@
 import org.ejml.simple.SimpleSVD;
 import org.javia.arity.SyntaxException;
 
+import java.util.LinkedList;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
@@ -630,7 +631,7 @@ private Object applySub(Object l, Object r) throws SyntaxException {
     private SimpleMatrix parseMatrix(String text) throws SyntaxException {
         // Count rows & cols
         String interior = text.substring(2, text.length() - 2);
-        String[] rows = interior.split("\\]\\[");
+        String[] rows = split(interior, "][");
 
         SimpleMatrix temp = new SimpleMatrix(rows.length, rows[0].split(",").length);
 
@@ -656,6 +657,33 @@ private SimpleMatrix parseMatrix(String text) throws SyntaxException {
         return temp;
     }
 
+    /**
+     * Apparently String.split isn't happy if the breakpoints are side by side.
+     * eg. 111, split on 1, returns an empty array. See: http://stackoverflow.com/a/28035974/1342672
+     * This function returns the correct array of size 4.
+     * */
+    private String[] split(String text, String breakpoint) {
+        LinkedList<StringBuilder> pieces = new LinkedList<>();
+        pieces.add(new StringBuilder());
+
+        while (!text.isEmpty()) {
+            if (text.startsWith(breakpoint)) {
+                pieces.add(new StringBuilder());
+                text = text.substring(breakpoint.length());
+            } else {
+                pieces.getLast().append(text.charAt(0));
+                text = text.substring(1);
+            }
+        }
+
+        String[] array = new String[pieces.size()];
+        for (int i = 0; i < array.length; i++) {
+            array[i] = pieces.get(i).toString();
+        }
+
+        return array;
+    }
+
     boolean isMatrix(String text) {
         String separator = getMatrixSeparator()+"";
         String decimal = getDecimalPoint()+"";

diff --git a/mobile/src/main/java/com/android2/calculator3/BasicCalculator.java b/mobile/src/main/java/com/android2/calculator3/BasicCalculator.java
@@ -44,7 +44,6 @@
 import com.android2.calculator3.view.DisplayOverlay;
 import com.android2.calculator3.view.EqualsImageButton;
 import com.android2.calculator3.view.EqualsImageButton.State;
-import com.android2.calculator3.view.MatrixComponent;
 import com.android2.calculator3.view.ResizingEditText.OnTextSizeChangeListener;
 import com.xlythe.floatingview.AnimationFinishedListener;
 import com.xlythe.math.Constants;
@@ -326,9 +325,6 @@ public void onButtonClick(View view) {
             case R.id.parentheses:
                 mFormulaEditText.setText('(' + mFormulaEditText.getCleanText() + ')');
                 break;
-            case R.id.matrix:
-                mFormulaEditText.insert(MatrixComponent.getPattern());
-                break;
             case R.id.fun_cos:
             case R.id.fun_acos:
             case R.id.fun_sin:

diff --git a/mobile/src/main/java/com/android2/calculator3/MatrixCalculator.java b/mobile/src/main/java/com/android2/calculator3/MatrixCalculator.java
@@ -15,16 +15,32 @@
 */
 package com.android2.calculator3;
 
+import android.os.Bundle;
 import android.view.View;
+import android.widget.TextView;
+
+import com.android2.calculator3.view.CalculatorEditText;
+import com.android2.calculator3.view.DisplayOverlay;
+import com.android2.calculator3.view.MatrixComponent;
 
 /**
  * Adds graphing and base switching to the basic calculator.
  * */
 public class MatrixCalculator extends GraphingCalculator {
 
+    private CalculatorEditText mFormulaEditText;
+
+    protected void initialize(Bundle savedInstanceState) {
+        super.initialize(savedInstanceState);
+        mFormulaEditText = (CalculatorEditText) findViewById(R.id.formula);
+    }
+
     @Override
     public void onButtonClick(View view) {
         switch (view.getId()) {
+            case R.id.matrix:
+                mFormulaEditText.insert(MatrixComponent.getPattern());
+                return;
             case R.id.plus_col:
             case R.id.plus_row:
             case R.id.minus_col:

diff --git a/mobile/src/main/java/com/android2/calculator3/view/CalculatorEditText.java b/mobile/src/main/java/com/android2/calculator3/view/CalculatorEditText.java
@@ -122,6 +122,30 @@ public void invalidateSpannables() {
         }
     }
 
+    @Override
+    public void backspace() {
+        if (getSelectionStart() > 0) {
+            MathSpannable[] spans = getText().getSpans(getSelectionStart() - 1, getSelectionStart() - 1, MathSpannable.class);
+            if (spans.length != 0) {
+                if (spans[0].removeOnBackspace()) {
+                    String text = getText().toString();
+                    int selectionHandle = getSelectionStart();
+                    String textBeforeInsertionHandle = text.substring(0, selectionHandle);
+                    String textAfterInsertionHandle = text.substring(selectionHandle, text.length());
+
+                    int deletionLength = spans[0].getEquation().length();
+                    String newText = textBeforeInsertionHandle.substring(0, textBeforeInsertionHandle.length() - deletionLength) + textAfterInsertionHandle;
+                    setText(newText);
+                    setSelection(selectionHandle - deletionLength);
+
+                    return;
+                }
+            }
+        }
+
+        super.backspace();
+    }
+
     public static abstract class SpanComponent {
         public abstract String parse(String formula);
         public abstract MathSpannable getSpan(String equation);
@@ -145,6 +169,10 @@ public String getEquation() {
         public boolean onTouchEvent(MotionEvent event) {
             return false;
         }
+
+        public boolean removeOnBackspace() {
+            return false;
+        }
     }
 
     /**
@@ -166,10 +194,10 @@ public boolean onTouchEvent(TextView widget, Spannable buffer, MotionEvent event
             int line = layout.getLineForVertical(y);
             int off = layout.getOffsetForHorizontal(line, x);
 
-            MathSpannable[] link = buffer.getSpans(off, off, MathSpannable.class);
+            MathSpannable[] spans = buffer.getSpans(off, off, MathSpannable.class);
 
-            if (link.length != 0) {
-                return link[0].onTouchEvent(event);
+            if (spans.length != 0) {
+                return spans[0].onTouchEvent(event);
             }
 
             return super.onTouchEvent(widget, buffer, event);

diff --git a/mobile/src/main/java/com/android2/calculator3/view/MatrixComponent.java b/mobile/src/main/java/com/android2/calculator3/view/MatrixComponent.java
@@ -78,9 +78,19 @@ public int getSize(Paint paint, CharSequence text, int start, int end, Paint.Fon
 
         @Override
         public void draw(Canvas canvas, CharSequence text, int start, int end, float x, int top, int y, int bottom, Paint paint) {
-            Drawable background = mContext.getResources().getDrawable(R.drawable.matrix_background, null);
+            Drawable background;
+            if (android.os.Build.VERSION.SDK_INT >= 21) {
+                background = mContext.getResources().getDrawable(R.drawable.matrix_background, null);
+            } else {
+                background = mContext.getResources().getDrawable(R.drawable.matrix_background);
+            }
             background.setBounds((int) x, top, (int) x + 500, bottom);
             background.draw(canvas);
         }
+
+        @Override
+        public boolean removeOnBackspace() {
+            return true;
+        }
     }
 }