Resolve manual update links from selected source

README.md

@@ -177,8 +177,8 @@ In the app:
 - If Android sends you to the unknown-app install permission screen, return to
   the app after allowing it; the app continues installing the already downloaded
   APK without another update check or download.
-- Open the `Update` page and tap `APK` to download the current public APK in a
-  browser.
+- Open the `Update` page and tap `APK` to resolve the APK from the selected
+  update source and open it in a browser.
 - Open the `Update` page and tap `Details` to see the installed version,
   selected update source, APK URL, install permission state, and a `Check
   update` button.

app/src/main/java/com/neatstudio/tmuxandroid/MainActivity.java

@@ -3,7 +3,6 @@ package com.neatstudio.tmuxandroid;
 import android.Manifest;
 import android.app.Activity;
 import android.app.AlertDialog;
-import android.content.ActivityNotFoundException;
 import android.content.ClipData;
 import android.content.ClipboardManager;
 import android.content.Context;
@@ -296,7 +295,7 @@ public final class MainActivity extends Activity {
         content.addView(actionPanel(
                 actionButton("Check now", view -> updateManager.check(true)),
                 actionButton("Source", view -> showUpdateSourcePicker()),
-                actionButton("APK", view -> openExternalUrl(BuildConfig.DEFAULT_APK_URL))
+                actionButton("APK", view -> updateManager.openApkDownload())
         ));
         content.addView(sectionTitle("Permissions"));
         content.addView(infoBlock("Android", permissionSummary()));
@@ -351,7 +350,7 @@ public final class MainActivity extends Activity {
                 "The app checks only the selected update source. APK downloads are cached by version and reused after Android install permission is granted."
         ));
         content.addView(actionPanel(
-                actionButton("Release page", view -> openExternalUrl(BuildConfig.DEFAULT_RELEASE_PAGE_URL)),
+                actionButton("Release page", view -> updateManager.openReleasePage()),
                 actionButton("Update source", view -> showUpdateSourcePicker()),
                 actionButton("Permissions", view -> showPermissionsAndUpdateStatus())
         ));
@@ -429,7 +428,7 @@ public final class MainActivity extends Activity {
             return;
         }
         if (PAGE_ABOUT.equals(activeMainPage)) {
-            actionRow.addView(toolbarButton("Release", view -> openExternalUrl(BuildConfig.DEFAULT_RELEASE_PAGE_URL)));
+            actionRow.addView(toolbarButton("Release", view -> updateManager.openReleasePage()));
             actionRow.addView(toolbarButton("Permissions", view -> showPermissionsAndUpdateStatus()));
         }
     }
@@ -1181,12 +1180,10 @@ public final class MainActivity extends Activity {
                 .append(")\n");
         text.append("Server: ").append(getServerUrl()).append('\n');
         text.append('\n');
-        text.append("Manual APK download:\n")
-                .append(BuildConfig.DEFAULT_APK_URL)
-                .append('\n');
-        text.append("Release page:\n")
-                .append(BuildConfig.DEFAULT_RELEASE_PAGE_URL)
-                .append('\n');
+        text.append("Manual APK download:\n");
+        text.append("Tap APK on the Update page. The app resolves the APK from the selected update source.\n");
+        text.append("Release page:\n");
+        text.append("Tap Release on the About page. The app resolves the page from the selected update source.\n");
         text.append('\n');
         text.append("In-app update:\n");
         text.append("Tap Update. The app checks only the selected source, downloads one APK per version, verifies SHA-256, then opens Android's installer.\n");
@@ -1229,14 +1226,6 @@ public final class MainActivity extends Activity {
         return text.toString();
     }
 
-    private void openExternalUrl(String url) {
-        try {
-            startActivity(new Intent(Intent.ACTION_VIEW, Uri.parse(url)));
-        } catch (ActivityNotFoundException error) {
-            showMessage("No app can open URL");
-        }
-    }
-
     private void showUpdateSourcePicker() {
         String[] items = {
                 "GitHub: " + BuildConfig.DEFAULT_UPDATE_URL,

app/src/main/java/com/neatstudio/tmuxandroid/UpdateManager.java

@@ -32,6 +32,10 @@ final class UpdateManager {
         void onMessage(String message);
     }
 
+    private interface ReleaseUrlPicker {
+        String pick(ReleaseInfo info);
+    }
+
     private final Activity activity;
     private final SharedPreferences prefs;
     private final Callback callback;
@@ -73,6 +77,40 @@ final class UpdateManager {
         });
     }
 
+    void openApkDownload() {
+        openSelectedReleaseUrl("APK", info -> info.apkUrl);
+    }
+
+    void openReleasePage() {
+        openSelectedReleaseUrl("Release page", info -> info.releasePageUrl);
+    }
+
+    private void openSelectedReleaseUrl(String label, ReleaseUrlPicker picker) {
+        if (checkInProgress) {
+            postMessage("Update check already running");
+            return;
+        }
+        String manifestUrl = getUpdateManifestUrl();
+        checkInProgress = true;
+        callback.onChecking(true);
+        postMessage("Resolving " + label + " from " + hostLabel(manifestUrl) + "...");
+        executor.execute(() -> {
+            try {
+                ReleaseInfo info = fetchReleaseInfo(manifestUrl);
+                String url = picker.pick(info);
+                if (url == null || url.trim().isEmpty()) {
+                    throw new IllegalStateException(label + " URL is missing");
+                }
+                activity.runOnUiThread(() -> openExternalUrl(url.trim(), label));
+            } catch (Exception error) {
+                postMessage(label + " failed: " + error.getMessage());
+            } finally {
+                checkInProgress = false;
+                activity.runOnUiThread(() -> callback.onChecking(false));
+            }
+        });
+    }
+
     private String getUpdateManifestUrl() {
         String url = prefs.getString("update_url", BuildConfig.DEFAULT_UPDATE_URL);
         if (url == null || url.trim().isEmpty()) {
@@ -260,6 +298,15 @@ final class UpdateManager {
         }
     }
 
+    private void openExternalUrl(String url, String label) {
+        try {
+            activity.startActivity(new Intent(Intent.ACTION_VIEW, Uri.parse(url)));
+            postMessage("Opened " + label);
+        } catch (ActivityNotFoundException error) {
+            postMessage("No app can open " + label);
+        }
+    }
+
     void resumePendingInstall() {
         File apk = pendingInstallApk;
         if (apk == null) {