Fixed #245: different padding between lines

library/src/main/java/com/tokenautocomplete/ViewSpan.java

@@ -2,7 +2,9 @@
 
 import android.graphics.Canvas;
 import android.graphics.Paint;
+import android.support.annotation.IntRange;
 import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
 import android.text.style.ReplacementSpan;
 import android.view.View;
 import android.view.ViewGroup;
@@ -12,56 +14,80 @@
  *
  * Created on 2/3/15.
  * @author mgod
+ *
+ * Updated on 15/04/2017
+ * Aleksandr Borisenko
  */
 public class ViewSpan extends ReplacementSpan {
+
+    private static final String TAG = ViewSpan.class.getSimpleName();
+
+    private static final char SENTINEL = ',';
+
     protected View view;
     private int maxWidth;
+    private boolean prepared;
 
-    public ViewSpan(View v, int maxWidth) {
+    public ViewSpan(View view, int maxWidth) {
         super();
         this.maxWidth = maxWidth;
-        view = v;
-        view.setLayoutParams(new ViewGroup.LayoutParams(
+        this.view = view;
+        this.view.setLayoutParams(new ViewGroup.LayoutParams(
                 ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT));
+        prepared = false;
     }
 
     private void prepView() {
-        int widthSpec = View.MeasureSpec.makeMeasureSpec(maxWidth, View.MeasureSpec.AT_MOST);
-        int heightSpec = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
+        if (!prepared) {
+            int widthSpec = View.MeasureSpec.makeMeasureSpec(maxWidth, View.MeasureSpec.AT_MOST);
+            int heightSpec = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
 
-        view.measure(widthSpec, heightSpec);
-        view.layout(0, 0, view.getMeasuredWidth(), view.getMeasuredHeight());
+            view.measure(widthSpec, heightSpec);
+            view.layout(0, 0, view.getMeasuredWidth(), view.getMeasuredHeight());
+            prepared = true;
+        }
     }
 
-    public void draw(@NonNull Canvas canvas, CharSequence text, int start, int end,
-                     float x, int top, int y, int bottom, @NonNull Paint paint) {
+    public int getHeight() {
         prepView();
+        return view.getHeight();
+    }
 
+    @Override
+    public void draw(
+            @NonNull Canvas canvas, CharSequence text,
+            @IntRange(from = 0) int start, @IntRange(from = 0) int end,
+            float x, int top, int y, int bottom, @NonNull Paint paint) {
+        prepView();
         canvas.save();
-        //Centering the token looks like a better strategy that aligning the bottom
-        int padding = (bottom - top - view.getBottom()) / 2;
-        canvas.translate(x, bottom - view.getBottom() - padding);
+        canvas.translate(x, top);
         view.draw(canvas);
         canvas.restore();
     }
 
-    public int getSize(@NonNull Paint paint, CharSequence charSequence, int i, int i2, Paint.FontMetricsInt fm) {
+    @Override
+    public int getSize(
+            @NonNull Paint paint, CharSequence text,
+            @IntRange(from = 0) int start, @IntRange(from = 0) int end,
+            @Nullable Paint.FontMetricsInt fm) {
         prepView();
-
+        // NOTE: only the first tag (measure) has ~2dp "padding"
+        // NOTE: a string with the single tag can be trimmed up to span height when the layout is inflated
+        String str = text.toString();
+        str = str.substring(0, str.lastIndexOf(SENTINEL) + 1);
+        if (start == 0 && str.length() > end) {
+            // WORKAROUND: first measure is ignored if there are other ones
+            return view.getRight();
+        }
         if (fm != null) {
-            //We need to make sure the layout allots enough space for the view
-            int height = view.getMeasuredHeight();
-            int need = height - (fm.descent - fm.ascent);
-            if (need > 0) {
-                int ascent = need / 2;
-                //This makes sure the text drawing area will be tall enough for the view
-                fm.descent += need - ascent;
-                fm.ascent -= ascent;
-                fm.bottom += need - ascent;
-                fm.top -= need / 2;
+            final int height = view.getMeasuredHeight();
+            final int top_need = height - (fm.bottom - fm.top);
+            if (top_need != 0) {
+                int top_patch = top_need / 2;
+                fm.ascent = (fm.top -= top_patch);
+                fm.descent = (fm.bottom += top_need - top_patch);
             }
         }
-
         return view.getRight();
     }
 }