Added pressure sensibility to stroke width computation

SignaturePad-Example/build.gradle

@@ -2,10 +2,9 @@ apply plugin: 'com.android.application'
 
 android {
     compileSdkVersion Integer.parseInt(project.ANDROID_BUILD_SDK_VERSION)
-    buildToolsVersion project.ANDROID_BUILD_TOOLS_VERSION
 
-  defaultConfig {
-        minSdkVersion 9
+    defaultConfig {
+        minSdkVersion 14
         targetSdkVersion Integer.parseInt(project.ANDROID_BUILD_TARGET_SDK_VERSION)
         versionName project.VERSION_NAME
         versionCode Integer.parseInt(project.VERSION_CODE)
@@ -18,9 +17,10 @@ android {
             minifyEnabled false
         }
     }
+    buildToolsVersion '27.0.3'
 }
 
 dependencies {
-    compile project(":signature-pad")
-    compile 'com.android.support:appcompat-v7:25.3.1'
+    implementation project(":signature-pad")
+    implementation 'com.android.support:appcompat-v7:27.1.1'
 }

SignaturePad-Example/src/main/java/com/github/gcacace/signaturepad/MainActivity.java

@@ -103,45 +103,9 @@ public void onRequestPermissionsResult(int requestCode,
         }
     }
 
-    public File getAlbumStorageDir(String albumName) {
-        // Get the directory for the user's public pictures directory.
-        File file = new File(Environment.getExternalStoragePublicDirectory(
-                Environment.DIRECTORY_PICTURES), albumName);
-        if (!file.mkdirs()) {
-            Log.e("SignaturePad", "Directory not created");
-        }
-        return file;
-    }
 
-    public void saveBitmapToJPG(Bitmap bitmap, File photo) throws IOException {
-        Bitmap newBitmap = Bitmap.createBitmap(bitmap.getWidth(), bitmap.getHeight(), Bitmap.Config.ARGB_8888);
-        Canvas canvas = new Canvas(newBitmap);
-        canvas.drawColor(Color.WHITE);
-        canvas.drawBitmap(bitmap, 0, 0, null);
-        OutputStream stream = new FileOutputStream(photo);
-        newBitmap.compress(Bitmap.CompressFormat.JPEG, 80, stream);
-        stream.close();
-    }
 
-    public boolean addJpgSignatureToGallery(Bitmap signature) {
-        boolean result = false;
-        try {
-            File photo = new File(getAlbumStorageDir("SignaturePad"), String.format("Signature_%d.jpg", System.currentTimeMillis()));
-            saveBitmapToJPG(signature, photo);
-            scanMediaFile(photo);
-            result = true;
-        } catch (IOException e) {
-            e.printStackTrace();
-        }
-        return result;
-    }
 
-    private void scanMediaFile(File photo) {
-        Intent mediaScanIntent = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);
-        Uri contentUri = Uri.fromFile(photo);
-        mediaScanIntent.setData(contentUri);
-        MainActivity.this.sendBroadcast(mediaScanIntent);
-    }
 
     public boolean addSvgSignatureToGallery(String signatureSvg) {
         boolean result = false;

build.gradle

@@ -1,12 +1,14 @@
 buildscript {
     repositories {
         jcenter()
+        google()
     }
 
     dependencies {
-        classpath 'com.android.tools.build:gradle:2.3.3'
-        classpath 'com.github.dcendents:android-maven-gradle-plugin:1.5'
+        classpath 'com.android.tools.build:gradle:3.1.4'
+        classpath 'com.github.dcendents:android-maven-gradle-plugin:2.0'
         classpath 'com.jfrog.bintray.gradle:gradle-bintray-plugin:1.7.3'
+        classpath 'com.android.tools.build:gradle:3.3.0-alpha07'
     }
 }
 
@@ -16,5 +18,6 @@ allprojects {
 
     repositories {
         jcenter()
+        google()
     }
 }

gradle.properties

@@ -33,6 +33,6 @@ POM_LICENCE_DIST=repo
 POM_DEVELOPER_ID=gcacace
 POM_DEVELOPER_NAME=Gianluca Cacace
 
-ANDROID_BUILD_TARGET_SDK_VERSION=25
-ANDROID_BUILD_TOOLS_VERSION=25.0.3
-ANDROID_BUILD_SDK_VERSION=25
+ANDROID_BUILD_TARGET_SDK_VERSION=27
+ANDROID_BUILD_TOOLS_VERSION=27.0.3
+ANDROID_BUILD_SDK_VERSION=27

gradle/wrapper/gradle-wrapper.properties

@@ -1,6 +1,6 @@
-#Tue Aug 08 11:36:01 SGT 2017
+#Thu Aug 30 09:23:55 CEST 2018
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-4.1-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-4.9-all.zip

signature-pad/build.gradle

@@ -3,16 +3,14 @@ apply plugin: 'com.github.dcendents.android-maven'
 apply plugin: 'com.jfrog.bintray'
 
 dependencies {
-
 }
 
 Properties properties = new Properties()
 final def bintrayPropertiesFile = project.rootProject.file('bintray.properties')
 if (bintrayPropertiesFile.exists()) properties.load(bintrayPropertiesFile.newDataInputStream())
 
 android {
-    compileSdkVersion Integer.parseInt(project.ANDROID_BUILD_SDK_VERSION)
-    buildToolsVersion project.ANDROID_BUILD_TOOLS_VERSION
+    compileSdkVersion 27
 
     defaultConfig {
         minSdkVersion 9
@@ -22,6 +20,7 @@ android {
     dataBinding {
         enabled = true
     }
+    buildToolsVersion '27.0.3'
 }
 
 bintray {

signature-pad/src/main/java/com/github/gcacace/signaturepad/utils/BitmapUtils.java

@@ -0,0 +1,51 @@
+package com.github.gcacace.signaturepad.utils;
+
+import android.graphics.Bitmap;
+import android.graphics.Color;
+
+public class BitmapUtils {
+    public static Bitmap trim(Bitmap source) {
+        int firstX = 0, firstY = 0;
+        int lastX = source.getWidth();
+        int lastY = source.getHeight();
+        int[] pixels = new int[source.getWidth() * source.getHeight()];
+        source.getPixels(pixels, 0, source.getWidth(), 0, 0, source.getWidth(), source.getHeight());
+        loop:
+        for (int x = 0; x < source.getWidth(); x++) {
+            for (int y = 0; y < source.getHeight(); y++) {
+                if (pixels[x + (y * source.getWidth())] != Color.TRANSPARENT) {
+                    firstX = x;
+                    break loop;
+                }
+            }
+        }
+        loop:
+        for (int y = 0; y < source.getHeight(); y++) {
+            for (int x = firstX; x < source.getWidth(); x++) {
+                if (pixels[x + (y * source.getWidth())] != Color.TRANSPARENT) {
+                    firstY = y;
+                    break loop;
+                }
+            }
+        }
+        loop:
+        for (int x = source.getWidth() - 1; x >= firstX; x--) {
+            for (int y = source.getHeight() - 1; y >= firstY; y--) {
+                if (pixels[x + (y * source.getWidth())] != Color.TRANSPARENT) {
+                    lastX = x;
+                    break loop;
+                }
+            }
+        }
+        loop:
+        for (int y = source.getHeight() - 1; y >= firstY; y--) {
+            for (int x = source.getWidth() - 1; x >= firstX; x--) {
+                if (pixels[x + (y * source.getWidth())] != Color.TRANSPARENT) {
+                    lastY = y;
+                    break loop;
+                }
+            }
+        }
+        return Bitmap.createBitmap(source, firstX, firstY, lastX - firstX, lastY - firstY);
+    }
+}

signature-pad/src/main/java/com/github/gcacace/signaturepad/views/SignaturePad.java

@@ -18,6 +18,7 @@
 
 import com.github.gcacace.signaturepad.R;
 import com.github.gcacace.signaturepad.utils.Bezier;
+import com.github.gcacace.signaturepad.utils.BitmapUtils;
 import com.github.gcacace.signaturepad.utils.ControlTimedPoints;
 import com.github.gcacace.signaturepad.utils.SvgBuilder;
 import com.github.gcacace.signaturepad.utils.TimedPoint;
@@ -60,9 +61,9 @@ public class SignaturePad extends View {
 
     //Default attribute values
     private final int DEFAULT_ATTR_PEN_MIN_WIDTH_PX = 3;
-    private final int DEFAULT_ATTR_PEN_MAX_WIDTH_PX = 7;
+    private final int DEFAULT_ATTR_PEN_MAX_WIDTH_PX = 10;
     private final int DEFAULT_ATTR_PEN_COLOR = Color.BLACK;
-    private final float DEFAULT_ATTR_VELOCITY_FILTER_WEIGHT = 0.9f;
+    private final float DEFAULT_ATTR_VELOCITY_FILTER_WEIGHT = 0.3f;
     private final boolean DEFAULT_ATTR_CLEAR_ON_DOUBLE_CLICK = false;
 
     private Paint mPaint = new Paint();
@@ -101,6 +102,7 @@ public SignaturePad(Context context, AttributeSet attrs) {
 
     }
 
+    /*
     @Override
     protected Parcelable onSaveInstanceState() {
         Bundle bundle = new Bundle();
@@ -110,7 +112,7 @@ protected Parcelable onSaveInstanceState() {
         }
         bundle.putParcelable("signatureBitmap", this.mBitmapSavedState);
         return bundle;
-    }
+    }*/
 
     @Override
     protected void onRestoreInstanceState(Parcelable state) {
@@ -211,17 +213,17 @@ public boolean onTouchEvent(MotionEvent event) {
                 if (isDoubleClick()) break;
                 mLastTouchX = eventX;
                 mLastTouchY = eventY;
-                addPoint(getNewPoint(eventX, eventY));
+                addPoint(getNewPoint(eventX, eventY), event.getPressure());
                 if(mOnSignedListener != null) mOnSignedListener.onStartSigning();
 
             case MotionEvent.ACTION_MOVE:
                 resetDirtyRect(eventX, eventY);
-                addPoint(getNewPoint(eventX, eventY));
+                addPoint(getNewPoint(eventX, eventY), event.getPressure());
                 break;
 
             case MotionEvent.ACTION_UP:
                 resetDirtyRect(eventX, eventY);
-                addPoint(getNewPoint(eventX, eventY));
+                addPoint(getNewPoint(eventX, eventY), event.getPressure());
                 getParent().requestDisallowInterceptTouchEvent(true);
                 setIsEmpty(false);
                 break;
@@ -270,6 +272,16 @@ public Bitmap getSignatureBitmap() {
         return whiteBgBitmap;
     }
 
+    public Bitmap getTrimmedSignatureBitmap(boolean transparent) {
+        Bitmap originalBitmap = BitmapUtils.trim(getTransparentSignatureBitmap());
+
+        Bitmap whiteBgBitmap = Bitmap.createBitmap(originalBitmap.getWidth(), originalBitmap.getHeight(), Bitmap.Config.ARGB_8888);
+        Canvas canvas = new Canvas(whiteBgBitmap);
+        canvas.drawColor(transparent ? Color.TRANSPARENT : Color.WHITE);
+        canvas.drawBitmap(originalBitmap, 0, 0, null);
+        return whiteBgBitmap;
+    }
+
     public void setSignatureBitmap(final Bitmap signature) {
         // View was laid out...
         if (ViewCompat.isLaidOut(this)) {
@@ -437,7 +449,7 @@ private void recyclePoint(TimedPoint point) {
         mPointsCache.add(point);
     }
 
-    private void addPoint(TimedPoint newPoint) {
+    private void addPoint(TimedPoint newPoint, float pressure) {
         mPoints.add(newPoint);
 
         int pointsCount = mPoints.size();
@@ -464,7 +476,7 @@ private void addPoint(TimedPoint newPoint) {
 
             // The new width is a function of the velocity. Higher velocities
             // correspond to thinner strokes.
-            float newWidth = strokeWidth(velocity);
+            float newWidth = strokeWidth(velocity, pressure);
 
             // The Bezier's width starts out as last curve's final width, and
             // gradually changes to the stroke width just calculated. The new
@@ -553,8 +565,9 @@ private ControlTimedPoints calculateCurveControlPoints(TimedPoint s1, TimedPoint
         return mControlTimedPointsCached.set(getNewPoint(m1X + tx, m1Y + ty), getNewPoint(m2X + tx, m2Y + ty));
     }
 
-    private float strokeWidth(float velocity) {
-        return Math.max(mMaxWidth / (velocity + 1), mMinWidth);
+    private float strokeWidth(float velocity, float pressure) {
+        float velocityWidth =  Math.max(mMaxWidth / (velocity + 1), mMinWidth);
+        return Math.max(velocityWidth*pressure,mMinWidth);
     }
 
     /**